OP, welcome to the Grande O'l USA (well almost). I spent the last 2 years living in Amstenrade NL (working in Brunssum) and am now back here. I got my Xpel put on in Tilburg.
I can offer this to you.
1. Free refills on soft drinks here - yes as much as you can carry internally out the door with you for all one price!
2. Tip your waiter/waitress 15-20% of the bill, tip is not included in the bill -- no "rounding up" here.
3. The food is MUCH better than in Holland and much more diverse.
4. Go to KFC here and you will notice the steroid fed chickens here produce a breast 2-3 times of the size of the "yard birds" they serve in the NL
5. Pot is not legal here (only in a few states) and it's still not Federally legal. Possession of marijuana is illegal in Pennsylvania
6. Lancaster PA is Amish country, go to an Amish restaurant and dine "family style". Check out Gettysburg and Hershey Park as they are not too far. Watch the 254 minute Gettysburg movie before you go and the sites you see will mean much more to you like little/big round top and hells kitchen. You will also enjoy seeing the Amish buggies all over the road and their weird looking bicycles.
7. Speaking of Bicycles - there are very few designated bike trails here in the USA and especially in PA but they have a lot of farm roads that have less traffic. Also drivers don't yield to bikers here like in the NL.
8. Driving - right is not right (as in they go first), right on a red light is allowed here
, also cant park in opposite direction on other side of road (park like you're in Germany).
Best of luck in your American adventure and report on your own observed differences when you get here.