Graduating Senior?

I have nothing to do over the summer, so I’m looking to try to do something career related, which is mechanical engineering. I don’t know if I want to do a summer program. Probably not since likely I’d have to pay for it, which seems like a waste of money for a graduating senior. Unless it’s a cheap/free program, I think my only options are a research internship/fellowship at a local college, contacting professors that stuff. I could also look at a specific company’s internship listings. Besides these, I don’t know what else I could do.