Have you taken the SeeD exam yet? The T-rexaur is good for leveling if you can blind him, but don't worry too much about it; you'll level plenty as you go, and monsters change levels to match up with Squall so you can't really get ahead like in other games. Fight a few extra guys and make sure to draw--you don't need to go overboard, and it doesn't take too long to get a good magic stop--and you'll be just fine.