Los Angeles native currently in Boston - Sub 40k Mortgages

Hi Bigger Pockets!

I am from Los Angeles, CA currently living in Boston, MA.

I have been reading about real estate investing on and off for the past year and have finally joined Bigger Pockets! A few colleagues have recommended Bigger Pockets and I have found the knowledge in these forums unbeatable!

My goal for this year is to continue learning about buy and hold REI and purchase 1 or 2 mortgages for $20k - $40k each - potentially out of state. I have been connecting with a family friend who has been buying and holding sub $40k mortgages in another state. For a first time purchaser, what type of home would be a good start: Single Family Home or Multi-Family Home? Are there any pros / cons with either?

If you have any suggestions on books, threads, or podcasts on sub $40k mortgage REI, I would love to know! Thank you and looking forward to networking with members of BP!