I'm about to give Marching Mand a chance but I think my resistince, high notes, and the way i rad music isn't good enough.
Any tips

My experience (a long time ago) was that marching bands required memorizing the music...at least for the competitive sector.

And not all the parts are high notes...when I had issues with range I'd play parts an octave down. The drum majorette and band director wouldn't like it when they noticed me doing that, but I'd always retort "do you want to hear me play crap or something that sounds good?"

Some of my most pleasant memories as a kid were from marching band. Don't be intimidated, just have fun!

what about resistance?

I am not sure we understand what you mean by "resistence". Are you resisting joining marching band? Is there lots of resistence on your trumpet? Are you pinching your lips too tightly together. Please try and explain a little bit more about what you are worried about.

Ok!!!well I pinching my lips a bit to much and I don't think that helps toward endurance. So what I'm worried about is not lasting long enough while we preform in marching band.

I think you could persuade your section leader without any trouble to give you a third trumpet part. It shouldn't be in your upper register.

Not to be sarcastic, but why don't we just stop pinching our lips? That's not the best embouchre for a good tone.

Remember the lips don't really vibrate against each other to produce a tone. They oscilate on the stream of air flowing between them. As you go higher you use faster air, not much tighter lips, but faster air and actually a little less air as you go higher not more air (big misconception).

If you can find my replys to post(s) on brace on or braces off that is a great exercise for you and your range.