I don't know how to make my window bigger :(

The red is the old top face from the window, which i moved up by extruding it to the height of the bottom green border. The green square is the newly needed face for the wall, which will incorporate the new higher window, and the one i’m having problems getting. When i try to select only those (green) vertices to create the newly needed face, the left border ends up selecting the bigger orange vertice instead (same on the right side), and if i fill it, i end up with the old big face instead of the smaller green one.

How do i fill up only the green face?

The top (pink) vertice didn’t actually exist before (i expected it to work nonetheless). I filled that one now, and then selected all 4, filled in the face, and got this as a result.

Oh it actually worked now when i only selected the top and bottom (pink on this picture). I still don’t understand why…

Looks to me you’re creating overlapping geometry. Prepare the .blend for upload and attach it. Instructions linked in my signature.
If you can’t share the whole thing, select the problem area and surrounding geometry, ctrl+i to invert selection, X -> faces and then save the file with another name.

Edit: Right. Looks like it’s getting solved. Still see how to upload the file - screenshots help when explaining the problem and asking questions but the file helps to answer them.

Will keep in mind for next time.
I seem to have gotten this problem to work fine for now.