If you’re careful and can’t just get it off with your fingernails, a razor blade is young best friend for scraping off stickers, if you’re less careful they sell plastic razor blades for scraping stuff that also work pretty well.
For residue, goo gone, cooking oil, isopropyl alcohol, lighter fluid, or just some soap and water if you’re careful. Or just let the residue wear off on its own if you’re lazy.