Hi there! I created this system to keep track of revenue during a fair our school had. It's essentially a Google Sheet system in which for every customer that orders, you select the order in the dropdown menu (and how much orders) — and the revenue will automatically be inputted and calculated. Hope this will help you in whatever way it can :)

View the system: (see for yourself here) https://docs.google.com/spreadsheets/d/1gsgtQatoCZ8qLucgwqNgZK0dMzlkkC5a/edit?usp=sharing&ouid=101476478834887782743&rtpof=true&sd=true

If you prefer a tally based report system through Google Sheets, you can check out my other project here: https://github.com/hdavidviloria/tallysalesreportgsheet

You can edit the dropdown list through data validation to edit the choices to what you are going to sell, and edit the pricing to match your needs. For example, for our booth, we sold some food and offered a nerf game (so, those are the choices in the dropdown menu). The cash in column will automatically calculate how much the cost (through a formula multiplying the number of products with how much it costs). For a closer look of how this works, you can view the formula of the “cash in column”.

If you're planning on creating something like this, hope this was able to give you inspiration :)