How long should I wait until I can turn the soil in Northeast PA?

Usually it's a matter of waiting until the danger of frost is passed so anything that is planted doesn't freeze.

You can clean it up as early as you wish, just be mindful of your planting zone. You don't want newly transplanted items to freeze in a cold snap. Do you know what zone you are In?

It's more difficult to work frozen soil. Just wait until you can did fairly deeply without reaching frozen area. Turn and let sit a while before planting. Old rules are made to be broken. I suggest you contact your County Extension Agent's office to get the best up-to-date information. They'll also be able to test your soil so you can amend your soil to grow what you want in the best way possible. Their services are free as it is a government agency. They may also be able to refer you to other's who will be willing to share plants with you.

You can turn the soil earlier than that if hasn't rained in a while and the soil is not soggy. Wet soil is heavy and sticks together, which is bad for subsequent planting. May 30th might be the last frost date for your area, after which you can safely plant out your seedlings. Go to this page to see where your area is on the hardiness zone map. PA is split into several zones, so your plant date may be earlier. This is for planting, not for turning your soil. https://planthardiness.ars.usda.gov

Same here in Michigan. I try to wait but it is soooo hard I am usually done by Mother's Day.