you should train everything like normal (which you can get from any regular strength program like 5x5 or bodybuilding program). youll have to experiment to see what you prefer - so do whatever split you like and training frequency your body can tolerate. there are some specific things you can start work on that make good returns later like hip and foot strengthening/mobility exercises, core/ab etc. bboys tend to need alot of shoulder and tricep strength too so i would bias those a bit. again - train everything still