I started out working business development for Marcus & Millichap (helped my sales skills and gen. real estate finance), did acquisitions and project management for a small real estate developer (learned acquisitions, increased my renovation knowledge), was an underwriter for Fund That Flip (developed strong real estate analysis skills), have been an agent for 3 years (gen. real estate sales understanding), and have flipped two properties on my own successfully and have 3 more in renovation currently.I launched my own company and now work full-time as an investor. 

Long-term, I would like to build some serious wealth, and I look at the first deal or two as a way to start developing the skills to do so. 

Instead, know your skills and your abilities and use that to help them and propose what you could do to help.

Find a way to leverage your skills in exchange for learning.

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.