I'm 16 and have this weird thing on my lip that looks like a blister i was butting my lip and in a matter of sec a little blister statred to grow?

Mucocele: You most likely have a mucocele, or a minor salivary gland that has become occluded due to the trauma from biting your lip. The minor salivary gland continues to produce saliva and appears as a translucent fluid filled blister when it cannot empty its content into the mouth.

Harmless mucocele: Usually they're not a problem and will go away on their own. If concerned see your dentist for examination and removal if needed