I understand you are trying to learn and not giving you a bad time, but this is pretty much stuff that is taught in basic business classes. I'd start reading basic business books. Not popular stuff that you can find on the internet, but actual real business books. Google "KPI", that's for sure - Key Performance Indicators. Look up ( "Periodic Business Report" examples ) and variations on that to know what they can be - I'm sure there are a ton of reports. The main thing is to have a lot of reports with numbers on them - results, statistics, all that. For example, you are going to want a sales report every day to see how many sales you have had, as well as the same thing on a weekly, monthly basis, too. That's really the most basic and what everyone is going to want to know. Maybe a profit report daily if the accounting department's systems can do that. But I'd just look up "business periodic reports examples"
Oh, I just tried this google search term, it is a good one: "what regular reports does a business need"
But google different variations on those keywords and others too.