Many things you can accomplish with tire prep when used correctly, grip, heat, softness, side bite, forward bite, can all be altered by tire prep.
Best thing is to get with a company you can trust and you feel comfortable with, who you can get info from easily. Next is learn what you can get from that prep and how it benefits you. Lastly is learn from the mistakes you make. All the best tire guys in the country have made mistakes, and some of he best still learn, thats how and why they are the best.