Tips for improving on the trumpet

Guys, could anyone give me some tips on how to improve on the trumpet? I've been playing in my school's marching band for about 5 months, but I feel like I can't evolve like the rest of my classmates. We started rehearsing for the World Cup, and I have to play the trumpet, which made me wonder if I'm the worst in my role. For I am the only one who will play the trumpet lll. It's important to note that my mind works slower, and sometimes I have memory blackouts, so my learning becomes more challenging. 😭