I'll be honest here man, don't even think about PVP unless you are prepared to pour money in this game like no ones business :) as F2P i can tell you that its impossible to actually compete at any higher level in PVP or any bigger PVP events because you just cant keep up with new meta ninjas witch costs hundreds of dollars and you power will never be as high as of those who spend thousands of dollars for power and so on. Just try to have fun as much as you can.