How to learn about table structure?

At my current job i track my own hours, as well as product taken at cost (it’s a food producing business) and expenses carried on behalf of my employer, so i can calculate a total owed to me at the end of the week.
I’ve been looking at timesheet app examples but can’t seem to find anything quite right even for just my own hour logging, let alone the other two requirements.

Some advice on a spreadsheet layout would be appreciated or even a point toward reading material on table layout, etc…

Thank you