@Roseann Koefoed,As long as you have legitimate self-employment or an active business, you will be able to establish a self-directed Solo 401k plan.

You'll want to consider this in light of your long term plans - i.e., do you want to have a portfolio of RE properties down the road, or are you expecting to cash out and do something different. 

How do you plan on using that financial tool?  

Will depend on several factors like the type of property, type of tenants, your risk tolerance, other assets you own, your estate planning, laws where the property is located, etc.

We plan to try it as a short term rental after the builder is out. 

I bought this property with a partner and we were planning on flipping it and putting it back on the market.

I plan on living in this with roommates for 2 years and going onto the next deal.

Lesson learned on going into business without exit plans, I guess...For reasons out of scope here, I just filed my 2021 taxes and the IRS hit me with a $30k capital gains bill (not including interest or penalties).

Or should I break my promise to get into real estate in 2025 and continue to work part-time while going to college to afford a conventional 30-year mortgage on my first SF and use the "Building Wealth Through Single-Family Homes" plan? 

I am planning to buy my first investment property.