Being sued by a debt collector?

I received a notice today that I had certified mail from the local court. I missed the mailman, so I called the court and they said that I’m being sued by a collector, which I assume is from a credit card that I had when I was younger. So… now what?
I don’t work, so they can’t garnish my wages, and the only property in my name is my car.
Should I sign for and pick up the summons tomorrow?
Do I need an attorney, or do I just need to show up in court?
Can I do this through the mail?
What is the best/worst case scenario?

Anything else that I need to know?