Hey there its Sanji.
Okay if you wanna know more about trainning read this.
A fast and easy way is water Trainning .
To do so click your water walk verb on the hud and then walk on the water you will need stamina to do this so put your points on stamina but no all equal out your stats if u walk into some 1 u can get more xp when walking or into a puppet.

Log Trainning

This method of trainning is just keep clicking hit so its pretty easy.

Kunai Trainnning

All you have to do is throw kunai at the log u can get exp fast by this way.

Killing NPC's

You can gain exp if u kill hollows,wolvies,bugs and the other ninjas out here.

This is all u really need to know about trainning.
So go out there and train