Start of my investing Journey - Looking for advice!

[Harvey Specter]

Hey all - 

Decided to join and start some conversations and get some guidance for the education side of my future in Apartment Building investing. 

As for my background, I have been in Commercial Property Management, and have achieved my RPA through BOMA. I have a background as an HVAC technician and have a general knowledge of facility maintenance and a solid group of contractors I could use as partners. (The other job I had was staffing large facilities for maintenance).

So why buy Apartment Buildings? Currently I'm maxing out my 401k every year and am looking for the next place to invest. I believe that my background lends itself well to this type of investing. I'm currently making ~$150k a year, and believe within the next 6 months, I will be getting a promotion, which will allow for further investments. I recently sold my first house for a $15k profit after 2 years of ownership (relocated for a new position within my company)

As for my plan? I am anticipating when I relocate, it will be to a much lower cost of living area, but my salary will stay the same and have a huge bonus potential (about 50%). My thought process is to start with a 4-plex type apartment building, being able to take advantage of the Owner-Occupied FHA lending down payment and rates. I do have a decent amount saved (55-60k), but was thinking I would put the minimum amount down to keep funds for any incidents/vacancies etc. As well as funding for the longer term. The goal of course would be that the 3 units in the 4-plex pay for the overall price, allowing me to dedicate what I've been paying in rent/mortgage into savings.

Ultimately, between the remaining money from the first deal, additional savings (~$2,500/month) x 12 months, and my first bonus, I would have a substantial amount to put down as a down payment on a larger Apartment Building (say around 20 units?).

My end goal is not to get rich quick, and I'd MUCH prefer to stay on a lower earning property with less risk than a high risk/high return.

I do have a solid understanding of everything from Cap rates, NOI, Rent Rolls, etc. But any advice that anyone can provide to prevent pitfalls in my overall journey, please let me know. I will probably do due diligence on a few properties and post it on here just to get some experience. If there are any particular books, websites, or videos you guys would recommend, please don't hesitate.

I'm excited to pick your brains and add any direct support that I can.