If you go to Presque Isle check yourself for ticks when you leave! You’ll be walking along beautiful wooded foot paths in an amazingly pretty park, but you gotta check for ticks.
They do deer culls in Presque Isle every year and take measure to lower the population but they’re obviously still there, it’s gotten much better in recent years though. There’s a large hunting community in the area which helps as well.
It is the same deal around Ohio Pyle/Luarel Highlands, just have someone rummage through your hair, check your clothes/skin.
Pymatuning and Conneaute are more geared towards fisherman, although each generally has a few nice beach areas where sand has been imported for swimming.
Erie is a massive lake with tons of sandy beachers, it feels like going to a freshwater mini ocean. I really recommend it, rum runners was always a neat bar to visit on the lake as well. There is a night life area in downtown erie, and there are tons of floating restaraunts from what I understand (boat tours w/ meals)
If you go to Presque Isle, you may want to stop in at Waldameer Park when you’re done with the beach! It’s an adorable little amusement park with free admission, if you want to ride anything you’ll have to pay, one of the best wooden roller coasters ever.
Keystone State Park has a swimming beach, have gone a few times and it’s never absurdly busy. Nice trails around there too. I think it’s about 45 minutes away from Pittsburgh.
Moraine State Park is about 45-50 easy minutes from the city, just off I-79 in Butler County. They have grassy beaches with sand for sunbathing and swimming, and you can rent a kayak or canoe if that appeals to you.