i have been told by many people different things like playing on your top lip will increase rang and better tonal quality and then i go to my local music store and they tell me that i need to play more off my bottom lip. so now i am really confused so i play in the center so any tips will help.

You will never get a correct answer, because any one position is not the correct answer. For years people argues about lip position and they will continue to do so. YOu need to find a lip position that works for you. You can start at 50/50 and then move to 1/3 top 2/3 bottom,and then try 2/3 top with 1/3 bottom. Spend two weeks on each position.

What I teach most of my brass students is place the rim of your mouthpiece on the bottom lip where the lip changes color from pink to flesh. Then where ever the top hits your upper lip is about the correct position. (This does not work well on large lipped individuals). But the concept is to let the upper lip find it's natural position, don't force it into any particular formation. Callet and Smiley have entirely different procedures that work for them, they're still contorversial but people are quite succesful with them.

I know a lot of pros and semi pros who when they are tired after hours and hours of playing will shift to a position with almost no upper lip at all in the mouthpiece. What they are doing is their upper lip is tired and strained, they use their bottom lip for support to hold on a little longer. It's a trick to get a couple more high notes out.

When you heard that you need to play on your top lip, that's correct, because it actually center's your airstream so you can get more vibration in the trumpet (thus better resonance, tone, and range). When they mean by playing off your bottom lips is basically jutting your lower jaw (generally pushing your upper lips a bit away from the mouthpiece for more flexibility); it's also high range stuff. But just do what works for you; if you want to switch, go ahead and do so, but you'll need to practice more too...

Best regards,
belltrumpetplayer19