Given today’s interest rates, a highly-leveraged arrangement (where you’re putting 3% or 5% down) probably isn’t going to generate any cash flow, so unless you’re comfortable with injecting money into the deal every month, I’d recommend accumulating more cash before you start investing.Generally speaking, a good place to begin is when you have enough for a 20% down payment, closing costs, and 3 to 6 months of reserves.

This will impact your costs and time commitment.Risk Tolerance: How much risk are you comfortable with?

Then, over time, probably a few months, start to determine who you would feel comfortable doing a deal with.

Get out of your comfort zone.

Medford (North Boston) happens to be a low supply/high demand market so I absolutely need to get more comfortable with consistent rent increases but those increases need to be researched and in line with the market. 

So it's really what you are comfortable with and what your investment thesis is. 

Get out of your comfort zone.

Quote from @Scott Mac: Safety - Inherit a fully paid for SFH, in decent condition, in the neighborhood you live in, and rent it out to long term tenants who you are comfortable with.

Get things in writing if you're not comfortable with what you see or hear.

I have STR investors in Florida making 25% cash on cash returns, long term rental investors picking up properties directly off the MLS and cash flowing day 1 in various states, and house hackers completely removing their housing payment from the picture allowing them to save for for the next property.The beautiful thing about real estate is there are so many ways to succeed and a plethora of strategies depending on your comfort level and how active you want to be.