I'm 13 and I need some basic popular songs but I can't find any PLEASE HELP.
Hello, 13-year-old; by the phrase "basic popular songs" I'm assuming you mean songs sung by your favorite artists. Those songs are ALL OVER THE INTERNET - but not for free. If you do find a free version of the sheet music, then someone has taken it and made changes to the original.
If I were you I'd go to Musicnotes.com and search for your favorite songs... at least you will be able to look at page 1 of those songs to ascertain whether you'd like to pay $5 for it...