Actually. If you wanted to transfer it to a pmg file, all you have to do whenever you save it, there should be a drop down arrow underneath the "save" button. The drop down arrow should be like "gif*" or something like that. Click that and change it to "png" and save it.
I've had trouble whenever I created a gif image and opened it in paint, I wanted to copy and paste it but everytime I did that, it was a weird dif color. So I had to change it to a png file.
Also, in gimp, whenever you open the gif file, multiple layers should open up automatically. I would look at tutorials on YouTube if you wanted to know how everything worked.
Sorry for all the explaining

Good luck!