I'll try a little. As George Gee said, you were probably dealing with
something that really wasn't a cell on the sheet. It was some kind of object
- a picture, a text box, any number of other similar things. So when you
moved your cursor over it, it became a 4-pointed arrow. That indicates that
you are over an object, and you can left-click and hold and drag that object
around on the sheet. The 'star' or 4-pointed arrow is just a way of
indicating that the object can be moved around on the sheet.
If you click on such an object normally it shows up with a kind of fuzzy
border that will have stretch points top/bottom center, each corner, and
left/right center. You can grab those and resize the object.
To copy those kinds of things, you do as George said: right-click and choose
copy then go to where you want a copy of it and click there and then
right-click and choose Paste.