Fired?

So yesterday I got fired from my job (I think). My supervisor told me they decided to "let me go" because "things just aren't working out." Then she said that I was welcome to re-apply if I still wanted to work at the store, just not for the department I was in.

Here's what I'm wondering: if a person is fired from their job, are they not disallowed from working there ever again?

But I don't want to pay a ton in legal fees.  Is there an inexpensive way to sue?