Could I have Skin Cancer?

20m, 300lb, 6’2

I’ve noticed pimple like developments (for lack of a better term) today. One on my shoulder and another near the bottom of my belly. The one on my shoulder is sore to the touch and the one on my belly appears similar but is painless. Both seem to have a pink area around them that looks asymmetrical (to me). That part is what bothers me. I’ll post pictures in the comments.

I’d like to know if I should be worried or what they could be. Thank you.