You can’t be shy. Put yourself out there and introduce yourself to the people you want to work with. If there’s a particular band you want to play with, ask if you can come to one of the practices. Using mutual acquaintances can also be helpful in finding venues to perform at and/or people to sing with.
These experiences can also help give you a sense of what kind of performances you want to do. You may discover that you would rather sing with a group or a band instead of solo.