All I know about trumpet is toot, bring this to Quora, they have experts there who knows what trendy in trumpet

blow harder?

im percussion i cant help you sorry

I got you fam. Ok i played on a 3c for almost the entirety of my playing life. You're gonna want to go for a smaller mouth piece. Shallower. Im no expect but every brand has different numbers and letters and shit. BUT!! Dont blame the mouth piece. I only needed a 3c and did just fine. I know plenty of players who could get up to dub G and A and sup C no problem. A shallow piece did help endurance. 7c is a good bet. Shilkee (cant spell) is good for playing lead jazz. I borrowed one for a production of legally blonde. Good luck

Honestly, the mouthpiece size shouldn't matter as long as it works. I'd recommend going to a music store and testing out multiple mouthpieces until you find one that's comfortable. I still play on the 7c I've had for years and am able to hit any note without tone problems. It all depends on your oral structure.