For very small holes, like from tacks or small nails, white toothpaste works if you don't want to go to the trouble of going to buy some spackle. Whether spackle or toothpaste, just put a dab on your fingertip and wipe it across the hole.
you can buy patches and mud over them - small holes you can use Spacleulite - considering how big the holes are you can hot patch them and or go stud to stud and cut out and put in sheet rock patches and tape / mud out .
Cut out the hole to square it then put a backer behind it to attach the patch piece,mud it,sand it,prime then paint! Simple repair,do it the right way,take your time,or it will stick out like a sore thumb!
Sheet rock mud and sheet rock and maybe seem tape. -If they are holes from screws and nails fill the holes with mud, wipe off any extra around the hole with a damp sponge and let it dry a day then finish with some medium sand paper. -If they are holes a few inches or smaller cut out the damaged area leaving a nice round or square hole then cut a new piece of Sheetrock to fit the hole. Put Sheetrock mud on the edges of the hole and piece then push it in flush with the wall. Let it dry for a day then finish it. -If the damage is larger squared sections can be cut out that go from stud to stud. Screw the new section in and mud and tape the seems. -Anything bigger than that involves replacing entire sheets.