usually if sombody in the EU learns to use the force on his/her own, they use the dark side because it's simply easier to use. Kyp Durron is a prime example of this.
Anyway, The thing that's great about Taris is that you can connect to the older games, and you get "discovered" by a jedi and/or a sith. If they both find you at the same time you could do quests for each group to see who you move on and train with. Then the second part of the tutorial, where you learn about force powers and their many many uses, could be at either academy.