[2021] Boggsy! I have two sub questions for you....

Checking on Subs in Training Rooms - please standby…

I haven't yet received an answer about subs in Training Rooms - though my instinct is to say that they won't be available in Training Rooms just yet. Please hang on for an answer to that.
People have been able to take Subs into Coop for a while now - and though you can't test specifics of certain things the same way as you can in Training rooms, you are more than capable of getting familiar with how the submarines function.

There are also guides released by World of Warships that tell you which buttons to push before you enter battle.
I assure you, the WASD mechanics are not a foreign language if you've already played the other classes. The difference is you now have an adjustable depth bar that functions much likek your throttle and requires a little practice to make best use of them tactically.
Torpedoes can be fired forward and backward without too much difference and the pinging mechanic doesn't take long to understand.
I'm sure Coop would be happy to have you! That's where I took out my first sub.

Anyone who gives you a hard time for practicing controls in Coop? You send them to BOGGZY!