I have some power armor but it says I need training to be able to use it....where do I train for it? I also have some Talon armor which seems to have more DR than my power armor but I'd still like to know. I'm assuming I train with the BoS somehow.

If you follow the main questline you'll eventually get access to the Citadel. Ask around there and they'll point you to the NPC who will hellp you with the power armor training.

Another way is to do the Operation Anchorage DLC, should you own it. You'll automatiically get the training when you finish it.

Yeah, there is a guy in the Citadel (usually in the courtyard) training rookies. If you ask him, you should be given the training.

And if your lazy and on PC open the console and type setPCcanusepowerarmor 1