I'm not from Pennsy, so I can't help with some specifics, but I'd bet it's mostly private land--which means landowner permission. That's the courteous thing to do, anyway.
I'd choose a rifle which can shoot a 50-grain bulet at around 2,000 or 2,200 ft/sec--less noise. You may get permission to hunt somewhere, but the noise level of a .223 or a real cartridge like the .22-250 or the .220 Swift can upset the neighbors.
Pennsy has long been known for woodchucks. The .22 Hornet and the .218 Bee were considered the cat's meow for this. (Cat's meow means Good Thing, and was contemporaneous with the Hornet and Bee. Right, Dennis?)
Many states separate their hunting licenses into categories, such as Small Game (cheap) and Large Game (expensive). Regardless, the hunting license is the only way you can put money directly into game management and research--and in some cases, even habitat improvement or public-land hunting opportunities. It's a worthwhile purchase even for an ANTI-hunter!
(For all the noise-levels about government loving and cherishing the environment, wildlife budgets are being cut back in many states.)
Anyway, with your license and written permission from the landowner, no game warden will do more than wish you a nice day. (Well, there are a few wardens who don't think any hunter ought to ever have a nice day...)
Now: Getting landowner permission is sometimes difficult, since there may well have been some fools around before your time. Ask in a rural gun store about woodchucks and coyotes, where they might be found, etc. Then, taking no guns, go knocking on doors. Explain that you know all about the difference between a cow or horse and a woodchuck or coyote. That you understand about not using a fence as a ladder (tears up the fence) and about leaving gates as you found them. Offer to trade out a bit of work around the place in return for permission to hunt.
(Funny. Guys will drive a $30,000 truck with $1,000 guns to a $3,000/yr deer lease, to hunt maybe four or five days. But they won't invest a weekend of "help" in order to be able to hunt year round for varmints on a 10,000-acre ranch.)
So there's a start.
Best luck, Art