Make a tape of yourself singing and ask yourself

1. Do I sing in tune? If not, then stick to funny songs.

2. Do I lack breath support so that the tone of my voice changes during a line? This is what makes singers sound amateur.

3. If you sound good, can you do it in front of a crowd?

If you think your singing is enjoyable, then I would recommend doing it. Variety is so important to a good show.