yeah idk...
What is the best move black can play in this situation?

Type pawn and king endgames or opposition in youtube and watch a video that explains this position :) this is one of the basic things that every chess player should know
How should white move in order to promote?
a question or a statement? if its a question, after Ke4, black has to move aside. this is a basic endgame thing
if it is whites turn, the position is drawn because if king to the side, the black king moves to block the white king over and over again. if it is blacks turn, white is winning because once the black king moves aside, for example Kd6, then Kf5. Ke7 by black trying to block whites advance, then Ke5. in the end, white manages to push all the way and does not stalemate. its called opposition and its a very basic and useful thing to know for all chess players. remember that the king should go before the pawn, because that uses sholdering (Kd6, Kf5, Ke7 Ke5) to get the pawn through. if the pawn goes before the king or is on the same rank as it, the pawn ends up pinning the black king down, and the white king has to protect his final pawn, so it ends up like this

After 1.Ke4 Black must stop the white king reaching one of the critical squares d5,e5 or f5 when white is winning easily.
The only move that achieves this is 1...{I pass}, but unfortunately this is not a legal move.
I got this wrong so many times on puzzles in the past. I understand this so much better now.

bruh rei
???????
yes very bruh
wwhat? bruh?

1. Resign or 2. Don't get too far from the pawn. Your opponent might mess up and you should take the chance.

In this position black should just resign. You can try to prolong the game and hope the opponent blunders, but this position is lost for black unless white blunders.

In this position black should just resign. You can try to prolong the game and hope the opponent blunders, but this position is lost for black unless white blunders.
The exact opposite of this is true. This position is a dead draw unless white knows how to win it. And a low rated player will almost certainly not know how.
White has exactly one winning move now. It would be madness to resign now. Even if white plays the correct Ke4, it's still worth playing a few more moves as it costs nothing.
How should white move in order to promote?