Lice spreads incredibly fast, so I'd tell your parents that you THINK you have lice. Let's not completely skip to conclusions. Just go check with a doctor to make sure it's not dandruff or something else.
Tell your parents that you think you have lice and ask them for help. There's special shampoo for getting rid of lice, so, if it turns out you DO have lice, try some of that. Also, don't share anything that has touched your head with anyone, just to be on the seguro side.
go to the pharmacy and get lice shampoo. (and if you live with your parents tell them. partly so they can help and partly so they dont all end up catching it too). lice wont kill you but its a pain in the bunda in you dont get it treated, so do something as soon as possible.
you do a lice treatment (this involves your parents). This includes using the lice shampoo and then using a lice comb comb them out and pull out the eggs. you may have to do this once or twice before you get rid of them. If your case is really bad probally talk to someone professional that would know how to get rid of them.