For your first times you'll probably do 30+0 so train with that but also do 15+10 because it's very similar
Classical time controls to prepare for OTB

I have never played OTB before and my ultimate goal is to join an OTB club later this year and actually be decent and hopefully play in some tournaments. I want to play a long time control and play the moves out on my chess board so I can get used to real pieces and the time control. What do you think is the most common otb time control?
It varies from tournament to tournament and even organization to another (like FIDE vs USCF). In all honesty, I find adapting to time control fairly easy once you get into the "mood" of moving slower and thinking a lot through. Maybe practice 1 hour per side chess games. Some events are shorter like 45/45, some are longer like G90 (game in 90; 90 min per side) and some are much longer like 2 hours per side, some increment or delay and then time added for reaching certain intervals like reaching move 40.
Adapting to the event time control isn't too tough for me, but the toughest "transition" is to avoid moving quickly for the time control. Practice something like 1 hour per side is probably solid practice. If you play a lot of blitz/bullet, then even 30 min games can be a step in the right direction.

For your first times you'll probably do 30+0 so train with that but also do 15+10 because it's very similar
Agreed. My local chess club usually has 3 games per night at 25/10 time control (or something close to that) and has some rated events occasionally. Usually the "bigger" events like a club championship or state championship etc. are the longer time controls over an hour per side.

I have already played 100s of 15|10s and 30 min games. I was thinking something like 45|45. I just want to know whats the most common OTB time control so I can play games with that time control.

I have already played 100s of 15|10s and 30 min games. I was thinking something like 45|45. I just want to know whats the most common OTB time control so I can play games with that time control.
Then you already have a decent start. The most common is probably whatever time controls your local chess club uses most since that is where you will likely play most of your rated games. Other than that, it really varies a ton for what "long time controls" actually is based on what event it is.

Thanks for the input. I think 45|45 is technically longer though. 45 seconds times 60 moves is 45 mins and that is for each side so its more like 90 minute time control I think.

Im going to start playing longer time controls, a few times a week to prep for my upcoming tournament. Maybe a few 30+0 and then 60+ and so on. I don’t think you can play them too much, might get really boring
I think as one expands his knowledge in chess he enjoys playing more longer time controls. At first you just look to make sure you're not dropping a peice and that your opponent didn't drop a piece . But then as you get better your looking at the pawn structure, pawn holes, your bad bishop, tactics seven moves down the line, deciding whether a sacrifice will give compensation and other stuff like that. And when your opponent is moving you can assess the position and lay out your plan.

Im going to start playing longer time controls, a few times a week to prep for my upcoming tournament. Maybe a few 30+0 and then 60+ and so on. I don’t think you can play them too much, might get really boring
I think as one expands his knowledge in chess he enjoys playing more longer time controls. At first you just look to make sure you're not dropping a peice and that your opponent didn't drop a piece . But then as you get better your looking at the pawn structure, pawn holes, your bad bishop, tactics seven moves down the line, deciding whether a sacrifice will give compensation and other stuff like that. And when your opponent is moving you can assess the position and lay out your plan.
And you found exactly what I'm working on right now... Still a blitz main though.

@red and @kingattacker3 I ended up doing 45|45 last night. Even though my opponent moved 2x faster than me he never abandoned and the game ended within 25 moves with me checkmating him.

Game 90 is pretty common. Definitely I would suggest nothing less than game 60. And train to use your time to carefully look over every move. Don’t worry about losing on time. Worry about blunder early.
... Longest I've done is 55+5 or 60+0...

Anyone free for a realllllllllly long game sometime soon? Been training with 30+30 games against friends.
I have never played OTB before and my ultimate goal is to join an OTB club later this year and actually be decent and hopefully play in some tournaments. I want to play a long time control and play the moves out on my chess board so I can get used to real pieces and the time control. What do you think is the most common otb time control?