How to Invest in Real Estate is a great book to read if you want a comprehensive overview so you can develop your strategy.Good luck!

Unfortunately, that has been contributing to the household income as much as I’d like so I’ve started looking into what my dad used to build wealth and support his retirement - real estate investing.

Also mold in the bathroom is common and can usually be cleaned with normal household cleaners. 

If you're solely relying on rental income or are you refinancing and taking a cut of that for your own household, cars, bills, vacation, investments, etc as you continue to reinvest. 

You have 3 other people in your immediate family that will follow your lead, as the first generation english speaker and from what it sounds like, the financial head of household.

Another thing to keep in mind is that you may want to only have on person on each mortgage as to allow you to have more available to the household. 4 per person for 8 total vice just 4.

It is hard to recommend even a good course when I know statistically an investor will not be successful.It is worth mentioning that one of the most comprehensive courses I took was by @Charles Parrish.

My goals are to build a second income for my family that will replace the lack of a dual income in my household. 

That plus the low growth rate in household income and the bad schools. 

There is a phenominal FREE rental property analysis tool (calculator) here at BiggerPockets:http://www.biggerpockets.com/recritic.htmlBTW - It allows you to enter all the expenses and is quite comprehensive.