I'm super worried I might have Hep C. Help plz!!!!!?

I got the hep shots when I was little. Do you get a shot for the C one b/c I'm pretty sure you don't... My friend was giving blood and they told him that he had it, but that it could be a false reading and they are now testing it again, but a more advanced test, so he won't know if he has it for a while. Is it only shareable by blood? Can you get it by smoking a cig after them? Plz answer. Super worried.