Hello benhunt72, I had a deeper look at this principle, but I often fail when the opponents pawns come into action.
Endgame Essentials: King Opposition

what can I do when I got to leave the opposition because the opponent has the possibility to draw a pawn or when the opposition field is an attacking field of a pawn?

When you can, take the opposition. When you need to retreat, do so, but stay in the same file as the opponent's advancing pawn (be as close to the pawn as you can, to not let the opposing king into position).
*behind his pawn I meant to say. Anyways, sometimes more than 1 move will draw but what I said before is the safest way. Sometimes you will just have a losing endgame where your opponent will take the opposition. The important thing is not to mess up when you have a good position in the endgame.
Sometimes when the pawn is too advanced even taking the opposition will not save you.

what can I do when I got to leave the opposition because the opponent has the possibility to draw a pawn or when the opposition field is an attacking field of a pawn?
Yes, what nklristic states is true: played accurately, that position should always be a draw, but of course there are many other patterns that require different approaches. I'm no endgame expert by any means, but if you'd like to share a particular game, I'd be happy to take a look for you.

I don't have problems in particular game. I do the trainings. Still don't know how to share the pattern. Using the app on my cellphone. The pattern nklristic shared I already made.

I think one mistake I use to make is to use the diagonal opposition even if I can take horizontal or vertical.

Now I got a particular situation and finally made it to share the picture. It´s white to draw. Taking the opposition on c1, e2, c2, e3 and then whites opposition is blocked by his own pawn.
If white starts taking the square opposition on a3 then d1, b3, c1 and another time the opposition is blocked by whites own pawn.
I really need to change ideas how to handle the opposition in relation to pawn draws. Don´t expect the solution.

This is not the thing of simple opposition. Here it is more complicated because this is not a king and a pawn vs lone king. It is true sometimes even before that position, you can try planning in a way to draw this, but here it mostly comes down to calculation.
Kc1 loses because he can eventually get the opposition because there are more pieces in play.
Every beginner should understand this simple principle! It will really help you to take control in the endgame, and could make the difference between winning and losing.