The small skin coloured papule on the side of my nostril does not get bigger but when scratfhed it does bleed and won't go away. what could this be?

Unusual growth: At your age, there are a lot of reasons for things to appear on the face including acne, enlarged pores, etc. You may have a simple skin tag there that is excess skin that protrudes like a tag. It would bleed if traumatized. Get to a doc and have them remove it. It is simple and fairly painless procedure that will end your worries.