newbie add altered image to a layer

[bbxrider]

please see attached, I have a jpg image with white background, l think I made all the white background transparent and now want to add the altered image to the 2nd layer in the project, but can't make it happen. maybe this isn't possible? thinking it should be simple but after trying for over an hour, coming here for help. tried moving it, copy/paste it, add it, etc. but no luck yet. the attached pic explain it best I think