I know how to use it. You just pop up the script menu, choose a new one and type 'l337 pokemon battle' and the battle system should be done.
Now, instead of asking how to use rmxp, look at a few games and investigate the events to see what they do. Try using rm2k3 before taking the big leap to xp, I was too scared to change over for several months.. When you have a problem with something, go to the help and requests thread and post your specific problem. Don't just go to the general discussion forums and say "Does anyone know how to use RPG maker?"
Thank you