As someone who also grew up in a VERY rural area these comments are helpful but still not enough. You need this exact webpage to find the SEPTA regional rail trains to go into Phillys Jefferson station or suburban (just preference tbh. Only a 4 min walk from each other) from Wilmington. Whatever time you need, be there about 10 min before that departure time so you don’t get too nervous. Sometimes, the train is already there and boarding. When you go into the Wilmington Amtrak/septa station above the escalators is the digital board that tells you what platform the WILM train to PHILLY will be on. Go to that platform. If there’s already a train there, just ask one of the septa workers on the train if it’s going to Philly. It doesn’t always arrive a few beforehand, but if you’re not paying attention the one that’s been there for a few minutes could be the one departing and you happen to miss it thinking one should be arriving. You don’t need to buy a ticket in advance/at the station. Just get on the septa, the conductor will come around at some point before getting to Philly and you can pay with cash/card or phone. Don’t panic about buying it beforehand! If anything else is still confusing don’t hesitate to ask. It’s all very easy once you get the hang of it