Database Error while connecting from Localhost

Did you check the error logs? What's the exact error you're getting?

Here are 2 links to videos to hopefully explain / illustrate better what I'm working with and the error I'm getting. I have the database file inside the project folder......? I'm not sure why that's there or what to do with it.

Link #1 - Trying to run on built-in PHP server and / or MAMP: https://youtu.be/5p43JyROUOs

Link #2 - Database file in Project Folder:  https://youtu.be/A7I2VEQPXtg