There is no musical profficiency requirement to be in a band. History is full of bands with mediocre musicians that have had huge success! The key is to just start the band, play some music and enjoy yourself. The more you practise together, the better you will become playing together. Playing in a band is a great learning experience, you learn alot about how music is put together. The most important thing to do is practise, practise practise, and you need to practise together to get that sound you are looking for. If you want to play in a band, just get yourself a band to play in and do it
Doc-Z