Hi Lisa, welcome

I'm not sure what you mean by 'how this all works' but I'll see if I can shed a bit of light on what it is to be a VA in general and hopefully that will help.
A VA is a business owner, so the way each of us operates is to establish a real business, a virtual assistance practice, and then market our business to industries or individuals who fit with what each of us has to offer as service providers.
Here's a
'getting started' thread that might help you as well.
Best of luck in all you do!