Threaded BB, on a bike as new as yours will have external cups with indentations like these (the indentations are for the tool you use to install or remove). They'll be very similar in appearance no matter what brand of crank you have:



Older threaded BBs don't look like that but your 2012 Trek will.

Press fit BBs don't have external cups that can take the tool like that.

Hope that makes sense.

As for the chain wheel question, I'll let others answer that.