Hi Victoria,
I'm pretty new at this so I get how this can be overwhelming. I think starting with trios is the best way to get a food forest off of the ground. Gaia's Garden has lists of suggested trios..i.e. fruit tree, nitrogen fixer, ground cover etc. with lists of plants. You will have to research each individual plant to see how it does in your zone. Also, if you do fruit trees and bushes research the most disease resistant. (cedar apple rust may be an issue in PA check out the liberty apple)
The Stefan Sobkowiak video really opened my eyes to thinking about the process. He is a French Canadian who uses permaculture principles on his orchard. I used his ideas and expanded them...it's a good start. I am using trios as a base from which to build. This has worked out pretty well as I am sheet mulching by hand. Creating islands of chips as a base is helpful if you aren't using machinery.
Watch this video if you like it you may want to purchase the documentary film on his orchard. Jump to 11:00 to skip the fluff.