At your age and with your dad's remodeling connections, I'd learn a skilled trade (electrician, plumbing, HVAC etc.) that would put you front and center for lots of renovation projects. 

However as@Dalyn Hazell mentioned, not all loan officers are skilled at working with real estate investors.

Sounds like you are building a strong RE portfolio and have developed some great skills that can translate to a lot of financial opportunities for you and your family. 

Sure, there are exceptions (mostly lucky), but generally when you are new you either need a high-end skill or money to be useful to others in the business when you have no properties or buyers.

It is surprising how much $$$ you can save when you acquire the tools and skill.  

There are some risks here, and success depends on your management skills and staying on top of things, because ultimately you will be responsible for paying the rent and/or any damages if the tenant turns out bad or fails to pay.Any of these strategies would help you gain experience that will build up your savvy as you save money. 

This will be much more valuable for you and lead to future partnerships and JV's with the investors you help all while learning the skills you need to succeed.

The key is to get a skilled investor-friendly inspector to make sure you have good plumbing, electric, structure, roof, and mechanical systems.

You need to figure out how much time you have and how to apply the skills that you have best.Here's an article I wrote that should give you some guidance:https://www.biggerpockets.com/member-blogs/10850/86621-six-steps-approach-to-getting-started-in-real-estateIf you need more guidance feel free to reach out as I'm in the process of creating  training on getting started with REI. 

However real estate is illiquid and takes a bit of skill to do.REITs: far more liquid, meaning you can get in and out faster.