I literally have no idea how to start implementing CC in my game as Sheik. Are there any basic or common situations where Sheik could CC to punish something?

Armada's Sheik used CC extensively, partly because he hasn't developed his Sheik very much so he relies heavily on smart use of the few tools he uses with it. Watch videos of him vs Lucky from Heir if you want to see live footage of intelligent CC. I use it a lot too, so watching videos of me would also work. Common situations: -Anyone jabbing you including jabbing your shield -Spacies' bair, especially because the crouch makes it hit you later than where they aimed so it's often weaker. I'm lazy and bad so I punish with dtilt / ftilt / dsmash but you could grab too -Any unspaced Marth move at low percents -Falcon weak aerials, you can also ASDI down first hit of nair -> CC second hit of nair -> dsmash or grab a lot of the time -Peach nair (careful if she starts using fair, but that has long startup so you can play around it in other ways) -Weak Puff aerials when spaced poorly (aka the not-Hungrybox slayer) and Puff utilt so she can't rest you -Sopo aerials if that ever happens -Almost everything any non-top-8 character (including an opposing Sheik) ever does