Make sure you have a good foundation on your horse - a good trot, lope, stop, response to seat and leg, soft in the face and bendy through the body, then you need to do TONS of SLOW work. This thread has a lot of good places to start. Barrel Racing Exercises and Drills.
Get yourself a good trainer. It sounds like your horse is still green enough to not have a solid foundation, and you have a lot to do before you're ready to see barrels. The good thing is your horse is a clean slate! You can work specifically on the things a horse needs for barrels and not have to "unteach" a bad habit.