Put One Picture On Top Of Another In Paint
Here we consider how to put one picture on top of another using paint.
Suppose we have an image as shown here.

On top of this image, we have to paste another image.

For this purpose, open the second image in paint.
Now by using Select Tool, copy the needed portion.
Next, open your first image in paint and try to paste earlier copied image.
If get pasted, place pasted image on first image as per your requirement.
If you want transparent portion of second image to be pasted, then under Select Tool, select Transparent selection.

That's all, by this way, we can put one picture on top of another using paint.