Prologue and Chapter 1: Problems begin in the summer

This story features an O.C. so please no hate. There are no Mary sues, I make my O.C.s realistic in personality. This a Gravity Falls fanfic. Warning: I change scenes from the actual show to include my O.C.
If you see any grammar or spelling issues, please leave a comment around there so I can fix it. And if you have tips to make a chapter or paragraph better, comment as well. I would love any advice to make this story better for readers!