Most likely Fordyce Spots …
Is it harmful?
It cause something?
I’m kinda scared. 
google Fordyce Spot and find out you’ll see
you don’t have to worry much if it’s fordyce spots
Fordyce Spots are a natural development to the penis following the onset of sexual maturation / puberty - they are completely harmless - they may fade in time, they may not, you may get more, you may not.
Once you reach the age of between 25 and 3 2 you will have a better idea if you are going to have these Spots - and whatever else naturally develops - for the rest of your life or not …