New to the site and mustangs, first upgrades?

I'm telling you some 3:55's, exhaust, and a supercharger will get you as fast or faster than most n/a guys. Combos change all the time as you'll soon learn. This will get you headed in the right direction. You can add the intakes, throttle bodies,..... as you go. As your car develops you can develop along with it. When your combo changes,and it will, you can do like the rest of us and sell old parts to buy new parts.