some of the things you should know.
the MC knows he is in a fanfiction, this means he needs to find out how things work. in other fanfictions where Harry immediately goes off to find his Dog father, he is either a person who knows how the wizarding world works, or he is reincarnated, or he time traveled to the past.
the MC in this story knows the movies and has read the books 1-7 at least once. does that mean he can tell you where everything is? no. like where is Gringotts? top answer Diagon Ally. how do you get there? thru The Leaky Cauldron. where is that? downtown London... and on it goes. if you go to the Harry Potter WiKi in the Notes and References section they give 6 sources, and one is a game... I think...
otherwise, the knight bus requires a wand, to send a magical letter requires an owl. Mrs. Figg. yeah, we didn't go there. that would require the floo and where do you think she keeps the floo powder. probably not out in the open, combined with all her cats which are partially to kneazle... instead of 'nice doggy' it's 'nice kitty' as we back away from all of those claws.
and no, I didn't think about including her in this story. any interactions between Mrs. Figg and Harry Potter were inconsequential and of little note.
in other notes, the 200 remaining KP. yeah, I wrote down what I wanted the MC to get and then I gave it some costs. I got those numbers from rolling some dice and using the values given as the numbers for the costs. I tried to keep the numbers proportional to the impact of the item, but I failed miserably upon further consideration.
all in all this story is for fun. so enjoy. and point out my mistakes.