[Nerull]

I'm soloing a sorcerer in BG1 (using BGTutu). Sure, sorcerer gets more spell slots, but I couldn't cast Sleep, etc. I only had Magic Missile, so not that great. The key is to be very, VERY patient. Hunt and peck, hunt and peck. Lure out one enemy at a time, then run across areas you have already explored, turning to shoot when there is enough of a gap. Save the Sleep spell for those situations where you accidentally lure out more than one or two enemies at a time. Sleep spell is THE 1st level spell at the beginning of the game. And never let the opponent anywhere near you. Run away (off the map, if necessary) if you are overwhelmed. With the respawning that happens in that first wilderness area you start in, I got to level 4 before I left for the Friendly Arm. Make sure to do as many of the noncombat (or low combat) quests early.