Keep Chugging on or Scale Back?

[Trevor Martin]

Hi all, noob looking for a little advice:

I'm 20 years old, first truly got interested in real estate investing in January of this year, and made my first SFR purchase in late February. Since then, I have made two more SFR purchases under the wing of a mentor (details below). They have been all-cash purchases so far, and my reserves are getting low. I probably have enough to buy one more home outright before I'll have to look into financing.

My question is for you seasoned investors; should I continue pushing on and being aggressive? Or should I scale back a bit and see how things pan out over the next few months? I'm currently looking at a couple SFRs, as well as possible getting into a ~10 unit multifamily with my mentor.

I've always been one to be aggressive and go after a new passion to the best of my ability, but at the same time, it's scary to see all of this cash tied up into real estate, and possibly look at getting into debt (albeit good debt).

My current holdings:
Single Family Home #1 (owned outright)
Purchase Price: $73,000
Rent/mo: $950
50% rule monthly cash flow (15 yr @ 2.8%): $78/mo
*Purchased this home before I knew of the 50% rule. Also, it is very updated in terms of big-ticket items.

Single Family Home #2 (owned outright)
Purchase Price: $62,000
Immediate Reno: $4,000
Rent/mo: $950
50% rule monthly cash flow (15 yr @ 2.8%): $137/mo

Single Family Home #3 (owned outright)
Purchase Price: $79,000
Rent/mo $1100
50% rule monthly cash flow (15 yr @ 2.8%): $120/mo
*Furnace, Water Heater, Roof, Siding, Flooring are all new in this property.

Should I continue expansion and possibly look into borrowing since the market is right? Or would you advise slowing down a bit to make sure there are no major hiccups as a young/inexperienced investor?

Thanks for your input!