Never played one. I have a psp go a ps3, pc, and android phone. id prefer the best one to start with be a handheld, but any device is fine. Ive heard good things about both disgaea and fire emblem series. are these good launch points?
Tactics ogre
FF tactics
Newer Fire emblem are on 3ds. If you don't have that then emulate the old ones. Never play those though. Get Xcom on pc.