Hi Amanda. I know what the other members are saying seems harsh. Nobody means and disrespect, but it's one of those things that you'll just have to take our word for - you'll understand after you've been doing this for a while. You'll probably be saying the same thing to the next new person.
Keep signing up for every company you see. Start with 50. Most shoppers are signed up with well over 100. If you don't see any shops in your area with a given MSC today, then you may well see them tomorrow, next week or next year as things change quickly.
Good luck and keep asking questions - just don't ask which company has shops for which clients or which companies pay best, are in your area or have the "best" jobs if you're sensitive to chastisement. All those answers will eventually be apparent anyway if you keep reading the forums.
There are two types of people in this world: Those who can extrapolate from incomplete data.