I took my car in to have the A/C fixed and now my windshield wipers don't work. What might be the problem?

2005 Ford Freestar

Is this something I can fix easily myself or should I just bring it back to the shop?

Just take it back to the shop. If you can't visually see anything unplugged it best to take it back. When you take it back and tell them, they'll probably tell the mechanic that worked on it and he will quickly remember he forgot to do something.