bongcloud
What would opening meta be if pawns couldn't move 2 squares

fianchetto anything
For sure, Nf3 b3, or g3 bg2 nf3. Maybe even an English with g3 and an eventually d3 c3 c4
I heard that everyone used to play 1.e3 e6 2.e4 e5, until the two-squares rule was introduced to simplify the opening process.
The center is still as important, maybe even more so, because lines will not open up as easily on other parts of the board. So I'd presume a lot of 1. d3, as after 1. e3, black has the option to play 1. ... Nf6 to stop 2. e4, while black can't prevent 2. d4. I'd also imagine there would be a lot of boring games with minimal pawn moves. Maybe a lot more London systems too.

i think maybe two knight openings would become incredibly commonplace
Dumb thought I randomly had