I am new to trumpet. I am self teaching. I keep coming across the fact that there is a difference between what my trumpet does and what is written. Can anyone make sense of this for me.

When I play a `C` as written on my sheet music am I actually playing a different note? Or am I supposed to be playing a different note?

Thanks guys.

If it is piano music, than a C would become a D on trumpet because of transposition.
If it is Trumpet music, than you might want to check your tone balance.

yay because your a Bb insterment along with calinet and tener sax so when you play a C low brass plays a Bb and alto sax plays a G, (it works with every note) it`s nothing to worry about band arageements are written in everybody keys so you don`t have to transpose anything