Newbie - Drawing Top Face disappeared after push/pill

Newbie here,

As a learning process, I completed a 2D drawing of a part which I want to eventually send for CNC machining.

I finished the drawing, and did the pull thing to create 8mm thickness, and then went to pull a surface that was to represent recess of 5mm.

After getting quite confused I have ended up with this model, and I am concerned to do anymore actions, as I have spent days getting this far and don’t want to lose all that work.

Can anyone tell where I have stuffed up.

Thanks :+1:
Disk Side Dropout.skp (111.3 KB)

Basics of SketchUp at Campus - learn.sketchup.com

The desktop edition has a SaveAs command where we can locally save various version of our models. I’ve not used the web edition much recently, but does it also have this command?

You also have some free space on Trimble Connect which stores each save as a separate version of the model file.