Muggle-born children receive their letters in person from a member of the Hogwarts faculty, who explains everything to the student and parents. - via Harry Potter Wiki

See I received this letter, and i read it. Now even if i don't think it is a prank, where do i get all this books and the cauldron etc. Cassarin told me that there is no personal visiting to explain it anymore. How do i get to diagonally when i don't know of the existence of diagone ally? Just imagine me, a 11 year old boy in Russia(my dads a Englishman thats why im enrolled in Hogwarts) in the middle of the far east tundra(Siberia), where he lives, with a letter: welcome to a wizardry school get yourself a cauldron you can bring a rat see you in Hogwarts. We can discuss this in pm if you like i don't want to fight or annoy you i just cant build a logical bridge here(witch is vital to a RP imho)
Kind regards Bear
Ps thanks for the help in advance and excuse my annoyance