I have one older duplex that was build in 1920 we bought for $72k, and it's still around $550 due to its age and it being a duplex.

I would, check the age of the liens against your state's statute of limitations.   

In addition to what you mentioned, I look at: crime rates and in what areas crime is most concentrated, % of renters vs. owners, age demographics, employment diversification, median income levels, home values rates looking for appreciation, economic activity such as development projects both commercially and residentially, rental rates, vacancy rates, landlord/tenant laws, etc.  

If you get one home a year you will well pass your prime income producing age where you have no day time job getting another mortgage. 

Opoulos or yours truly was born in West Jordan but moved to Sanpete county Ut at the tender age of three.

That's discrimination and is against the anti-discrimination laws.

Given the age of home, etc, I would agree on the prior comment on cap ex.

I aspire to help my age group(21-30) build generational wealth through real estate investing while being able to invest myself.

I have a strict pet policy -- a well-trained dog, over 1 year (no puppies for sure), breed restrictions per my insurance, vet records showing age, breed, current vaccinations, required city license, and pet interview with landlord (me) or K9 good citizen certificate. 

Wish I would have started at your age.