Er, I am unsure of whether this is a joke or not, but I will treat it like it is real. That substance is called semen, and it is used for impregnating a woman, to make a child, but only when one is ready for this, and when one is old enough.
Im 12 and a sticky clear substance came out my penis?
It could be prelube.it's usually sticky and ckear. This substance may or not may contain semen.