Drawing fails because of small mistakes :(

Sometimes I can’t draw what I want, like here where it’s not possible to made wholes in the wall without one whole side of the wall dissapears. I know I must have made some small, small misstake somewhere that makes it like this, but it’s so hard to find out where and how. Anyone got any tips how to easier fix it…?

The file:
3D Warehouse WINTER-SUN-2

In the whole model… and they are not small at all.

Start with the basics of SketchUp at learn.sketchup.com

What do you mean I need to do? I have SketchUp 2017. This is all I see if I choose Entity Info:

Normally, if you follow the Campus tutorials (link above) and learn the basics of SketchUp, you would probably realize what mistakes you made when you created that model. You can also search in Google using the texts in red in the image from the previous post and learn about them.

Do not leave loose (raw) geometry, to avoid accidental sticking/moving to another one.
Once you have learned to group each constructive element (wall, floor, door, window, etc.) and assign it a tag, you will see that you work much easier, correctly and problems like the ones you wrote about you will meet less often or not at all. Identical repeating objects, make them components.
Orient the faces correctly, with the white facing outwards, and get used to working in the Monochrome style. Only after you finish modeling do you change the style to Shaded With Textures and start applying materials.

All these are basic things, valid in any version of SketchUp.