In this excerpt, there are a few grammatical errors and some awkward phrasing. Here are a few examples:
"Today A friendly Wizard, Harry Potter, Greated me" should be "Today a friendly wizard, Harry Potter, greeted me."
"it's my first day" should be "it's my first day,"
"didn't quite know my way around yet" should be "didn't quite know my way around yet."
"But luckily, I met a nice wizard who showed me around His name is Draco Malfoy" should be "But luckily, I met a nice wizard who showed me around. His name is Draco Malfoy."
"Which is pretty cool" should be "Which is pretty cool."
"he said I would be sorted into Slytherin with him" should be "he said I would be sorted into Slytherin with him,"
"his whole mood changed from excited to hatred as soon as the hat said I am a Gryffindor." should be "his whole mood changed from excited to hatred as soon as the hat said I am a Gryffindor."