Time Tracking Dashboard Vanilla HTML CSS and JS

I have never used a JSON file before and I figured out how to import the file but when it came to using it I was not sure of the syntax and the correct use. I know how to display each item individually but I was unsure of how to get it all functioning seamlessly. I did lots of googling and testing but my code just did not work so I completed the project in the way that I know how. A quick rundown of how to use a JSON file in JS in this scenario would be appreciated. Thanks.