To get from zero to baseline, I'd find a book and read it. I like "No Nonsense Landlording", but there are many to choose from.
The reason I suggest a book is that a book tends to be fairly broad and balanced, so rather than searching for individual topics (and having resulting "holes" in your knowledge), take the curated learning approach and read a book first.
At the risk of adding to the "holes" problem, in many states in owner-occupied housing, you have more freedom to choose tenants without running afoul of discrimination laws. I'm not saying that to suggest that landlords should discriminate, but more than 100% of your profit swing will come from good tenants over bad tenants, so make sure you know and follow your local laws (of course), but spend time thinking about the tenant profile you want. Most profitable tenants are probably not 800+ FICO score, single adult, no kids. Those might be "easier", but "easier" and "most profitable" are not necessarily the same thing.