Hey, so I applied to MIT early action and I was wondering how they feel about AP Physics 1.
I’m really interested in Physics, but my school only offers AP Physics 1 
I took what was available to me, but I couldn’t find anywhere to take AP Physics 2 or C. The few online programs I found that offered the course were charging WAY too much, and because my school wasn’t “partnered” with them or whatever I would have to pay the full amount.
Will MIT know that there’s only one AP Physics class offered at my school? I didn’t write it anywhere on my application… 
Yes; schools generally send out a school profile whcih lists, among other things, the most advanced courses offered by department. Neither MIT, no any other college, has any expectation that a student take a class which is not part of their HS’s curriculum.
You can ask your GC to mention in his/her letter that the school only offers AP Physics 1. Our school profile just lists “Physics” in the list of AP courses. My son asked his GC to mention that they have never offered AP Physics C, and that he’s requested to take it every year after taking AP Physics B in 9th. (They will only offer a course if 25+ students request it, and the most they’ve had is 14.)
As an aside, it’s annoying enough when a student says AP Physics without clarifying. It’s super annoying IMO when the HS can’t list it correctly on the school profile or in the course catalog.