We regularly vacation in the next county: Lancaster County PA, heart of the PA Dutch- Amish- Mennonite- what have you.
They are ordinary folks who just believe in a simpler way of life. There are some rules you should observe: Pay cash if possible, checks otherwise, but many stores in this area take Visa-- they do like tourist money! You will find things priced fairly but not cheaply.
Don't take their pictures but DO wave to the little kids in the buggies. Around here they always wave back! Pictures where they cannot be identified ( their back) are ok.
No business transacted on Sundays or Holy Days like Good Friday or Ascension Thursday. Lots of buggy traffic on Sundays: drive very carefully!
The baked goods are so awesome because they are all made from scratch with no preservatives and all natural ingredients. Don't be afraid to stop in at their small groceries. They are plentiful because a horse can only travel so far to get groceries! Again, take cash, but you wil be amazed at the unique and good tasting items on the shelves.
I recommend stopping at a leather/ harness shop for belts and gloves. The one in Intercourse, PA, ( yes that is the name of the town) actually has a sign on the door 'No Tourists" but they sell the sturdiest belts and the softest driving gloves. We found it by asking the ladies at the local bakery we frequent ( Dare I give them some advertising?) The Stolzfuss Sisters Bakery. They don't have a phone but they make better pies than my mom did ( and hers were awesome.) Everything is run on gas, no electricity. Three elderly sisters operate the bakery and DH delights in dishing out harassment to them and they shove it right back to him with extra. They frequently suggest he mop the floor for them

We usually stop at the beginning of our vacation and give them a large order for the day we are going home.
Check out any benefit dinners or auctions in the area too. Your money is welcome and helps support the community

DH and I attended a benefit auction a few years ago where we were some of maybe 6-10 English in a firehall filled to the brim with Amish. Had a simply awesome time and got some good deals. It was run on the honor system: keep track of your purchases and put your check in the box. Simply beautiful and incredible in this day and age.
For those people in SE PA, I recommend the Gap Fire Co Ham & Oyster supper coming up in April. They feed 2000 people family style in one afternoon. All homemade. Leave room for the cake and ice cream- family style.
We have also bought bird houses, yogurt, root beer, fresh veggies and fruit trees on our trips.