Welcome to the Community. QuickBooks offers a variety of reports that help you streamline your work with ease. I'll be happy to share more info so you can continue to do the things you love.
Based on what you've described, I recommend checking out the Profit and Loss report as it can be filtered to view your gross sales for a particular month or months. In case you need to customize/filter the report to view monthly gross sales, here's an article that shows you how to do that.