We're getting a ton of first time multifamily buyers coming here to San Antonio from California. I see a lot of them struggling with a few different things, depending on what size they are looking at:
If you are looking at 2-4 unit properties, one of the biggest issues is getting a good handle on the finances. A lot of these properties are owner occupied and self managed. Getting real data on lease rates and other market terms is extremely important with these properties, because you won't get real financials most of the time. You will get a copy of the leases during your option period, and that's about it.
If you are buying 5+ unit properties, then you have to be good at analyzing their financials, or work with an agent and lender that will take the time to work through those with you. Don't ever take projections in an OM at face value. You see a lot of T3 or annualized RR income with T12 expenses. This may or may not be a fair way to look at a given property. If the units aren't separately metered and there isn't a RUBS in place, then you definitely need multiple years of expenses to make an informed decision.
There is really a lot to learn about multifamily, and I would say it's more important to build a strong team than it is to learn every detail. This includes getting your property manager and lender involved early in the process. It also means working with an agent that is knowledgeable in multifamily (I'm assuming you're talking about small enough properties that there is a buyer's agent involved in the process. Once deals get bigger, those go typically go away in my market). I would start with something smaller than you can safely afford. You will learn so much going through the process.