Pawns are the hardest to master it.
Don't worry about them for now
depends on your goal in moving the pawn. if you just want to develop it then moving the pawn 2 places is usually better. (it's very circumstantial). 1 space pawn moves tend to be more passive but can be better.
A lot goes into judging a pawn move correctly. Not only does moving a pawn have positive and negative impact at the same time, the positive middlegame aspects can be negative endgame aspects and vice versa.
Think about which squares the pawn will never again be able to control after moving. Think about diagonal(s) you'll never be able to make a pawn chain on after moving. Consider which files, ranks, and diagonals you're openings and closing. Consider which pieces (yours and your opponent's) you're blocking, restraining, or making room for. Think about how mobile the pawns chain is, how vulnerable the pawn, and the chain is, how close to queening the pawn is. How close to the center, and close to the edge it is.
I don't memorise any openings (so I don't know which is more relevant for what) so I tend to move 2 spaces as default and one only to block a bishop or defend another pawn.