The rectangle is outside of the wall group and shows the effect z-fighting.
According to the tooltip, the wall behind your rectangle is in a Group. You have to open a group for edit before you can draw things that interact with its contents. Another clue is the strange shading, called “z-fighting” which occurs when two separate faces are at the exact same location. That isn’t possible unless they are in different contexts (model, group, or component).
Thank you!! Ugh. I seriously appreciate it! There seemed to be a hidden object that I had to deselect and delete. Also the trick of editing the group really helped. I use Adobe Illustrator and often if I go over my mouse the hidden objects can come through and I can easily deselect. It doesn’t seem to be the case with this program and it’s hard to work through all of this. I genuinely appreciate the help!
Adobe Illustrator is a 2D graphics program whereas SketchUp is a 3D modeling program. There are a lot of notions from 2D that don’t apply when working in 3D! The tutorials should help you to learn the differences.
It’s a bit hard after years of working with strictly 2D to then conform to 3D.
I have to learn to disregard everything I learned and start over. I am glad that YouTube exists though! Thanks again for the insight.
Groups and Components are a core concept in Sketchup that you will need to understand to progress. And for your own sake do not try to use SketchUp tags like Illustrator layers, you’ll have a mess on your hands. If you are looking to get more focused than YouTube:
https://learn.sketchup.com/track/sketchup-fundamentals-part-1