You really need to talk to your parents about hedgie's care...because a little illness can progress quickly and get serious, and hedgies need routine vet care (at least once a year) to ensure good health anyway by catching any possible illnesses early.
Sneezing can be a sign of a respiratory infection, which can get serious if left untreated. I would try to convince your parents to take him to the vet now before it gets worse (and the vet cost therefore gets higher). If he starts licking his nose/having a runny nose, he definitely needs to see the vet.
I wouldn't trust any antibiotics from a non-prescription site, personally, even if you can get them. I would rather go through a vet and not just wing it on my own.