Ok I just went down a very deep internet rabbit hole and went from believing google definitely sells data to it doesn't sell data to it sells data (kinda). I'd recommend this article on RTB's which explains how google advertisements actually work and how they leak your data (including your location).
I'd also recommend watching the short video by Brave linked in the article - I didn't understand the first part but the actual article explains it quite well, the end is the juicy part.
Hope this helps!
Welcome! :)