When would be a good level to switch to battlemode? i'm level 8 right now (

) and I really need to get exp faster than the big monster room in haunted house 2 ._. (By the way, how the hell do you switch to battle mode anyways? I couldn't find anything on the forums nor the help command on GK)
Also, should I prepare my naginata of bile +3 or should i get a better weapon? o.O
I know I shound like a newbie, but I havn't played GK for almost 1 and half year and only being able to play in weekends is killing me X[