All images u can find on google and so on are copyrighted. All of them have a owner. You can't resell something that is not made by u.
If you want to be original and pro ry to design everything, from a scratch. Then you won't have problem with the copyright. The dots, lines and colors are not copyrighted. LoL. So if you want to sell designs try to make them, then sell. Don't take images from sites and sell them somewhere else.