I think it's good to make teams with your friends and fight versus each other in the arena. It would be good to be on teamspeak with someone who knows what to do and who could be instructing you. Also, you have to remember that PVP costs. Such training may cost you a lot of ssa's and might rings, if you really want to learn how to tank in an artificial situation. Nonetheless, it's worth it because you will be more confident in actual war situation later on.