How to copy and paste a selected area on GIMP?

This is a bit freer version of Apple's philosophy.

Ive been using Photoshop professionally for about 20 years and find it
confusing to use GIMPs way of doing this. I was able to do what I think
you are requesting by doing the following steps:

Make a selection with the "Rectangle Select Tool"

Select "Edit" > "Copy"

Select "Edit" > "Paste As" > "New Layer"

Now that it is pasted and a new layer, you have to tell the layer to be
the same size as the image...

Right click on the layer you just created and select "Layer to Image Size"

or...

You can just right click on the layer you want to copy and select
"Duplicate Layer" and edit that layer however you like.