Paint by Numbers kits were first d in 1951 by Max Klein who was the owner of Palmer Paint Company. Because we didn't have all of the sports stores that are available within the United States, we had to make due with second hand equipment. Typically, above ground pools are less expensive to buy, install and maintain.
Wallpaper with any sort of metallic element or sheen to it, won't enable the paint to adhere towards the surface. If the caulk is challenging to remove, apply a layer of caulk remover towards the caulk bead. Another important consideration is if you should use primer. Some wallpapers, may use a coating on them, meaning that the paint wouldn't adhere to its surface.
None of which will leave a sufficient finish for your paint.