In the meantime, just focus on filing the vacany of the first property you bought and get familiar with what it's like to own a rental property first.  

I am a current college student and gained interest in real estate as I am working on a project focused on finding ways to expand opportunities for real estate investors.

This approach will allow you to focus on the financial benefits rather than the day-to-day operational tasks.Additionally, consider how this rental income will contribute to your overall financial picture.

from my advice rural properties and developments aren't successful and you are climbing an uphill battle. sounds a little niche. we focus on developing and not reinventing the wheel. if this is truly what you want to focus all your time and energy on then visit the closest 5-10 of these that look like the ones you are interested and ask if they'd expand or build a secondary one. do a lot of research before you just take action 

We are focused on families and want to sleep 10 or more.

I would focus on homes with dysfunctional floor plans.

@David R Pustelnik recommend you first focus on raising the rent for the first time in 10 years.By the way, how much have your property taxes and home insurance gone up since this tenant moved in?

Focus on durability over bells and whistles—tenants prioritize functionality and reliability.

With just three properties, do you think it’s worth hiring a CPA or tax specialist who focuses on real estate?

Maybe but for now I think the lessons we are learning and what we want to focus on have taught us well.