I havent relocated for opportunities but have some experience with Mid-term rentals - For MTR I would find major hospitals and then search the houses around them, if they are priced really high / numbers wouldnt work, eliminate that market.

Eliminate debt, establish a budget, and save.

One of the biggest mistakes I see investors making is they forget to address things like HVAC, siding, etc when they have access to a hard money loan.

That's how you gain the information you need to AVOID MISTAKES. 

Let’s just say I want to avoid rookie mistakes before I take the plunge.Looking forward to hearing from all the experienced (or even not-so-experienced!)

I don't expect to know everything by then, but I hope to develop a basic strategy that prevents me from making the most common and costly mistakes that a newbie can make.

So I gravitate toward things that are well understood, proven, time tested, tie up all details in a nice neat little package, and eliminate as many variables as possible. 

That would minimize and maybe eliminate the need for a loan for those properties.

I fully understand there are consequences for my mistakes and I own up to that.

Seller Pre-Sale Financing: Consider selling the tenant-occupied property "as-is" now to an investor, perhaps at a slight discount, which could save time and eliminate renovation costs.