The coach will decide whether or not you pitch often. So if you want to pitch, you should talk to the coach about whether he thinks it would be worth it for you to do some specific work (either inside the program, or private lessons) for pitching.
What high school team are you on this year? Remember that on any team, the players change from year to year - it could be that they need your pitching one year but not the next, depending on who else they have.