Advice on SharePoint Structure

Hi, I'm new to SharePoint and I'm not sure how to structure things to make it simple for my employees.

Each active project has it's own Team, for ease of archiving and permissions so that Teams isn't so cluttered for employees. This creates a new SP site for each project. We also have a main SP Team and site for everyone (except certain lists that have permissions) and a Management SP (for use on Teams).

Our main site currently houses our master lists, including the master project list. Our projects are data heavy, so will need multiple lists. I'm not sure if it's best to create all of these on the main site so the information is in one place, or project-specific information on each project site (I'm guessing the former?).

Once I work out my structure, I guess I need to use Power Apps and Power BI to show the collated information for each project in one place? I'm going to need some good guides I think!