I've never felt so anxious doing something legal. In fact, I was so nervous that I ended up spending way too much money and bought a lot more weed than I wanted.

Like most Americans, I've never bought legal marijuana before, so I didn't know what to expect when I tried it a few weeks ago during a visit to Washington state. It wasn't like going to a liquor store, where aisles are stocked with drinks you've seen advertised millions of times. And it was nothing like a bar, despite the guy at the door checking IDs.

It must be how a non-coffee drinker feels walking into a Starbucks (SBUX). Except there wasn't a menu telling customers what's for sale at the shop I visited in Seattle, called Cannabis City. That's one reason why I was so flustered.

A friend and I waited on line outside the store for about 15 minutes before we were told to step inside to the counter on the right. We were slightly confused about what this "counter on the right" was all about. But something about having a bouncer at the entrance who allows only a handful of people in at a time made us think we shouldn't mill about. We made a beeline to the right.

Inside looked kind of like a jewelry store, with merchandise inside glass cases. There was one salesman standing behind our counter. He appeared to be assigned to us, sort of like a bank teller.

He said hello. Then there was awkward silence. I scanned the case in front of me, there were only a few different types of weed -- without any kind of description. Was this all they had? Were they supposed to give you different kinds of highs? Was I supposed to know? Could I ask?

After what seemed like an eternity, I said I wanted to buy an eighth -- because I heard that's what people usually ask for. The sales associate asked how much I smoke. I said "not a lot," so he suggested the two strains with lower levels of THC: Green Crack and Sage. I said I'd take both.

He rang me up. This little adventure was going to cost me $88. Already embarrassed about how this whole process had gone down, I laid down my Amex -- forgetting that dispensaries don't accept credit cards. Not a smooth move.

Recreational pot is legal in Washington and Colorado and now, thanks to successful ballot initiatives this week in Washington D.C., Alaska and Oregon, it will be soon be legal in those states too.

But it remains illegal on the federal level, so credit card companies and banks, which are regulated by the feds, hesitate to work with pot businesses.

At Cannabis City, it's cash only, or you can use the ATM. So the store charged my debit card $90 and gave me the $2 back in cash for the four grams (a little more than an eighth of an ounce) of pot.

But they did give me two free lighters. Score!

Interactive: Where pot is legal