How to get smooth skin?

my butt and legs skin is not smooth...do you guys know how to clear my skin? like it has stretch marks(white ones) and it looks like wrinkled..is there anything I can use? I want my skin too look fresh and smooth..sort of like the modles lol I dont know if they use make up to cover all the stretch marks..I want my skil like Brenda Asnicar.. here is the link to see the picture.. I dont know if its possible just want to make my skin look better.. thank you! http://www.fanpix.net/picture-gallery/brenda-asnicar-picture-16267973.htm