Right sided stomach pain after eating could possibly related to a problem with your gallbladder, but without more information, I could not be certain.

the pain is more towards the front of my stomach. I'm also overweight so my parents think it's stretching muscles which is causing cramping. Does that help anything?

I would doubt that it is due to stretching muscles, because when you are overweight you aren't stretching muscles to accomodate for abdomen size. Typically you are stretching skin. Furthermore, the pain would probably not increase with eating if it were muscular. Being overweight does, however put you at risk for gall bladder disease. Other factors include being female, being over 40, and eating foods higher in fat. You might mention gallbladder to your physician when you are seen.

I looked into Gallbladder disease and it says that most young ppl don't get it and im only 19. does this matter?

It is true that it is more common in women over the age of 40, however, younger people can have this problem as well, particularly if their diet consists of food which is higher in fat content. I had my gall bladder out at age 31.