How to clean-up after boolean modifier is applied

[jootly]

I am a noob so my question is probably stupid but here’s the problem:
I want to make a concrete wall. So i made a cube and to make holes in it i mad a few meshes for the holes. When i apply a boolean and delete the hole meshes, i get the shape of the wall that i wanted, but when going to edit mode the wall is a total mess as far as the edges go. How can i fix it. please help. The second pic is before i applied the boole and the first one after:

[Richard_Marklew]

If you are not bothered about having ngons select all edges and X / Limited Dissolve. Blender cannot have faces with holes in them so you will still have some connecting edges present