I'm 11 and just finished my first novel — be brutal

I'm 11 and this is my first novel. I'd love honest feedback, good or bad. Be brutal. Ok maybe not THAT BRUTAL. My book is about a kid called Brian who always asks questions and comes up with crazy theories. Here is the link : https://docs.google.com/document/d/1XuE8c_EDQI8LT3XhNtMwpMFQWHdw82a8GyPSOmK7ltM/edit?usp=sharing

So I started writing only a little while ago and have made some small books here and there. This book is my biggest. It has 112 pages and 16 chapters.