Scratches=if u can feel it with ur finger nail it needs paint if you can't feel it with the nail you can usually hide it with the buffer or get it out with some sanding and the buffer.
Stickers=adhesive remover might have to buff afterwards to try and get the rest of the paint to blend a little better. depends on how faded the paint is around the sticker.
Dents= call a dent remover, there are some home remedies like plunger or tool from parts store tho.
Sap= clay bar & buffer
Stains= good degreaser scrub brush, carpet extractor with a heater works excellent and i like to buff the material dry with a towel.
these are all just my opinons, results vary from car to car. good luck hope this helps.. + welcome to FRF, lots of good info on this Forum