Major security threat, Your connection wont matter, its your upload that will matter! And Is your pc even on 24/7? I suggest getting hosted on a proper server, like mine lol. PM me if you need cheap hosting. Also, if your keen on the whole pc issue (baddd idea) Get apache on your system and got get a ftp server.
Lol......what is your upload. Almost all connections are 256k and son, thats crap. And if your pc is "like" always on, then thats not going to be a good host. And ye, many tutorials if you google " apache, php setup".
Dont see how 15 is too young for hosting? Where do you live