Forty million people on Friday morning woke up to a locked down-California, grappling with new rules about what to do and where to shop as the state battles the coronavirus pandemic.

At a press conference late Thursday, when Gavin Newsom, the California governor, announced a shelter-in-place order that asks people to stay home unless absolutely necessary, he said the rate of coronavirus was doubling every four days in some areas of the state. The degree to which the hospital system will be overwhelmed will depend on how Californians respond to the restrictions, he said.

It was a dramatic escalation in the state’s attempt to curb the spread of a coronavirus the governor said could over the next eight weeks infect 25.5 million people – more than half the state’s population.

Non essential-traffic at the US-Mexico border, the busiest port of entry in the US, had been halted on Friday as both countries sought ways to defend against an unseen virus.

A few minutes north in Chula Vista, where a city councilman has been hospitalized after he was infected with coronavirus, police use drones rigged to loudspeakers to enforce the lockdown.

The usually bustling state Capitol rotunda in Sacramento is empty. Photograph: Rich Pedroncelli/AP

Los Angeles was a shadow of its ordinary self. Famously gridlocked freeways stood virtually empty, prompting bored-at-home Angelenos to open Google Maps just to marvel at the rare green sight of uniformly traffic-free roads in the middle of the day.

The traffic reduction led to significant improvement in air quality as smog and pollution dramatically declined. Across LA county this week, the air was consistently ranked as “good” quality, instead of at levels officials deem “unhealthy” for many, which frequently dominate the region in normal times.

At the Wine House, a prestigious outlet for wines and spirits in West Los Angeles, staff were quick to shoo out the last lingering shoppers shortly after the restrictions took effect, telling customers that orders would be strictly by curbside delivery from now on.

“They say we’re not an essential service,” an Italian wine specialist, Lance Montalto, said as a colleague hastened to lock the doors. “In a crisis like this, I think we should be.”

Their economic worries matched that of the city’s small army of waiters, bartenders and restaurant hosts who were laid off a few days ago. Many of those restaurant workers are also aspiring actors, but auditions and shoots are off the agenda as the TV and film industry screeched to a stop.

One of LA’s most prominent chefs, Nancy Silverton, announced that she was turning one of her restaurants on Melrose Avenue into a relief center for laid-off restaurant workers that would provide 300 high-quality meals every night for the next two weeks, paid for by the whiskey company Maker’s Mark, along with a variety of household essentials.

Wearing a mask for protection against the coronavirus, Henry Powell heads to his car after shopping at a Safeway store in Sacramento. Photograph: Rich Pedroncelli/AP

Up north in Sacramento, the first day of shelter-in-place felt like a weekend-come-early.

The clangs of the passing trolleys and beeps of the pedestrian walk signals echoed in the downtown area’s near-empty streets.

The typical steady flow of pedestrians had slowed to a trickle, with few still pacing the sidewalks with dogs and grocery bags. Parking, a precious commodity in California, was plentiful, with lines of meters blinking blankly next to swaths of spaces. The Capitol Mall, usually buzzing with activity on a weekday, sat quiet and peaceful under blue skies, few cars and even fewer people passing by the state house.

Downtown Sacramento businesses generally heeded the governor’s advisories early on, with bars and brewpubs closing down earlier in the week. On Friday, some restaurants with their chairs stacked on top of their tables were open for take-out and delivery only. Some bars were completely dark, with gates pulled down and shuttered.

“Downtown is kind of a ghost town,” said Shane Nicolette, 27, a barista at Temple Coffee Roasters. “Over the last week, it’s been a progression of state workers and people who work downtown, figuring out how they can work from home. Now it’s kind of integrated into everything over here.”

On a typical weekday, Nicolette would serve up to 500 people. On Friday, he served 50.

“It’s been a struggle for everyone,” he said. “We’ve had to cut hours back, way back. And when you work for tips, it’s a huge impact going from a line out the door to one person every 10 minutes.”

Other businesses downtown have already started letting their workers go. The manager on duty at Rodney’s Cigar and Liquor Store, who asked to be identified only as Bob, said he learned right after the governor issued his shelter-in-place order that he lost his other job working as a parking attendant at the downtown Marriott and Hyatt hotels. “It’s been rough, really rough,” he said. “I got to find some place else, some place unaffected. We’re all looking for some place unaffected.”

The lack of business as usual downtown made the presence of Sacramento’s homeless population stand out in sharp contrast. None of the unhoused individuals approached by a reporter said they had heard from the city, county or state about coronavirus, or about washing their hands, nor had they received any hand sanitizer.

“I just know what I’ve been hearing from the past week out on the street from other people,” said Thomas Mitchell, 44. “I didn’t even know the coronavirus was here until it was already here.”

Mitchell has already suffered a stroke and a seizure while out on the streets, as well as the stomach flu. He’s not worried about getting coronavirus.

“I’ve been out here eight years,” he said. “I’ve already been sick. So be it.”

The Grand Lake in Oakland theater displays a message about Donald Trump and the Coronavirus on their marquee. Photograph: Josh Edelson/AFP via Getty Images

But while the rest of the state comes to terms with the new restrictions, life seemed to be slowly taking on a new, if altered, sense of normalcy in the Bay Area, where a shelter-in-place order took effect on Tuesday.

Midmorning, two medical students at the University of California San Francisco stationed themselves at a typically busy corner of the city’s Mission District, soliciting N95 masks. They made sure to stand six feet apart, a distance enforced by a tape measurer they’d extended.

Behind them, dog-walkers and parents with children enjoying a warm spring morning dotted the usually crowded Dolores park.

Even as workers nailed plywood over windows of nearby shops, the video-rental section of Fayes coffee did brisk business.

“We’re telling people if you want to leave your house once this week and rent 15 movies, we’re not going to be charging late fees,” said the store owner Justin Lawrence.

Life had re-emerged, too, on the trails and sidewalks lining Oakland’s iconic Lake Merritt.

Sidewalks filled only with radio silence on Monday night had been reanimated by Friday morning, as bikers and joggers awkwardly navigated a 10-ft sidewalk while trying to observe social distancing norms.

Nearby, Amber Fina, 30, was organizing clothes in the tent where she sleeps. She said she’s lived through similar restrictions amid a hurricane in her native Florida, but the lockdown in Oakland was posing unexpected challenges.

“It’s making it impossible to get money. Not that many people are out, and if they are nobody wants to get close to you to hand you money. I need to eat,” Fina said.

Fina held up a bag of purified water and a bottle of sanitizer, which she said two healthcare workers delivered when they came through the encampment this week to take her and her neighbors’ temperature. Police have been kind, she said, coming around to ask if she needed services. They haven’t chased anybody off the encampment, she said, not even when the guys three tents down set a fire near their tent earlier this week.

Two construction workers near a playground smoked as they took a break from a project underway. One of the workers, Greg Stevens, said he was happy for the work.

“I’m more worried about everyone losing their minds and panic-buying everything,” Stevens said. “Did you see the crowds at gun stores? I’m an avid shooter, but c’mon. To me, that’s the dangerous part. People losing all reason.”

Families arrive at West Oakland middle school to pick up grab and go meals during the Oakland unified school district shutdown. Photograph: Kate Munsch/Reuters

Kendall Shotwell looked on as her two-year-old son Rider, wearing a hat that said Little Dreamer, ran in circles in a nearby playground and hopped on the scooter he’d commandeered from another child.

Shotwell’s husband is also in construction and works as an electrician, but he’s been off work. Unlike Stevens, who was working on a residential project, deemed essential under the new restrictions, Shotwell’s husband was working on a commercial, and therefore non-essential, project.

How long is this really going to last...That’s my biggest question Kendall Shotwell

Shotwell said she’s grappled with the ethical and moral quandary of letting Rider outside to run and play, while also adhering to the state’s guidance.

“I know the order lasts until 7 April, but how long is this really going to last, and when can he see his grandpa?” she said. “That’s my biggest question. Along with how much people can really take and where the breaking point is.”

In the meantime, Shotwell said she’s trying to live by her grandma’s advice to make lemons into lemonade and enjoy “the great indoors”.

Later in the day, Rider has a playdate scheduled. He’s going to FaceTime with his pals from preschool.

Mario Koran reported from Oakland, Vivian Ho from Sacramento, Peter Lawrence Kane from San Francisco, and Andrew Gumbel and Sam Levin from Los Angeles.