I'm mixing two topics in this one post! I just played in church last Sunday. The original plan was to have me play my arrangement of "Les Berceaux" by Faure for a Lenten service. We had played it last year, so the director just asked me to show up 20 minutes ahead of the service to run it. No problem, especially with a slow piece like this one. But when I showed up, she also gave me a piece for communion that was in concert treble clef. It had a melody and a descant. She asked if I could do it and I said "Yes." Below are the two videos. I was glad to have the 2nd piece because I thought it was a nice effect and added some variety. Therefore, it was good that I often practice reading concert treble (I would have had to at least think twice if it had been in alto clef, although I would have still said "Yes" on a simple piece).
But the other point is about playing opportunities. The basic rule is: when you get a chance to play, say yes, and be ready to do a good job. That will make you popular with various people who could offer more opportunities for you. In the CG Band I played solos in a lot of unpleasant situations, and I always had a solo or two in my pocket that could be programmed quickly. Band directors LIKE that (Arthur Lehman said much the same thing). Some folks in the band were a little resentful of the number of times I got to play. However, they were folks who did not want to play a solo at noon in downtown Oklahoma City on a concrete patio with no shade, as just one example. They only wanted to play if it was a nice hall, or maybe if it was a nice bandstand outside, and if the temperature was comfortable. That limited their opportunities. So try to stay flexible; keep some solos handy (that are quick for an accompanist/group to work through); keep your chops in reasonable shape; learn to play at least standard bass and Bb treble, and I strongly suggest being able to read concert treble; etc. To me, the rewards were worth it.
Les Berceaux:
https://youtu.be/ctA6ncNp85U
Communion Hymn (sheet music shown below)
https://youtu.be/WmI7rTCFFwQ