Can a 12 yr old walk into waitrose and buy a venus razor?

heya! =) im a 12yr old girl and i need to shave as i am going on holiday where i will have to wear vest tops and my underarm hair will be embaring me. so can i just walk into waitrose supermarket, grab a razor and pay (in my school unifrom aswell) ???? i really really need one so please give me ideas thanx :)