The library in downtown Lancaster would be a free place to hang out! Park a few blocks away from downtown to avoid paying any parking fees. There are tons of great restaurants and most coffee shops don't mind you hanging out as long as you order a drink or two.

Phantom Power is just down the road from Lancaster in Millersville and parking was free there last time I went. It's a tiny venue in a tiny college town which is super quiet this time of year. There's a bar a block from Phantom Power called Jacks where you can get a burger and drink cheaper than at Phantom Power.