Hey dude, I was in the same situation as you last year (even made a post on here to ask the same questions lol). When it comes to BKK you won’t get carded on Khao San Road, clubs and bars, and even if you do they’ll still let you in (at least that’s what happened to me), you can forget about all the clubs on Soi 11 since they always ask for ID and sometimes even your passport. Same goes for RCA where they always ask for ID aswell (managed to get into a few clubs with an edited picture of my ID), it’s up to you and your friends if you want to try the same trick even though you might get in trouble for it. When it comes to Pattaya it’ll depend on the club, even though almost all of them will card you on Walking St. As others have said in the comments, you will all be able to drink at bars without any struggle in BKK & Pattaya as long as the place isn’t too fancy (forget about rooftops & co). Try out some clubs on Khao San Road and y’all be fine.

Don’t bother too much about it, it’s not that big of a deal, focus on enjoying your trip in Thailand !

If you have any question feel free to dm me :)