How do i get rid of acne scars and marks? PLEASE ANSWER!?

i have them all over my upper arms. my mom says it looks like a disease. please name some medical treatments or creams that can be recommended by dermatologists. preferably inexpensive treatments because my dad lost his job and we need to conserve as best we can. anything in the thousands is definitely out. also what is dermabrasion exactly? what does it do? ill take all helpful answers! thank you!