I believe that this is a more personal question, unless it's on homework. Nevertheless, here you go:
Being a library aide means that I could help the community indulge in reading.
If I were a library aide, then I could teach youth how to understand a library.
I love to read, so if I was a library aide, I could apply my love.
These may seem a bit advanced for elementary school, or even middle school. And if this is a personal answer, I think you should try to think of your own!