Hello in 2021 my partner and I bought an apartment in FL.The main purpose of the apartment was to invest our money to have it saved for our son to go to college.We have been renting this apartment to a family member who has been paying less than what we pay for mortgage and HOA,so we have been taking money out of pocket to cover expenses and so on.I decided that even thou the purpose of buying it was for college,I’ve had enough taking money out of my pocket to pay the HOA and expenses.My question is if I should sell this apartment or if it would be worthy in the long run to keep it and meanwhile just keep paying the HOA and expenses.Renting it to another person is not an option.

that's the most powerful way to start. period.and there is absolutely nothing wrong with saving - most people can't even do that! 

With that said, it’s important for you to first establish a vision of the guest profile that you are trying to attract to your property before you dive in any deeper.

If it shows well, tell her you’d like to advertise the unit and schedule a day/time window of showings asap and that you can be flexible or even eliminate the early termination fee if you can rent it quickly.

Not sure whether it will be even allowed with the accepted cash offer?! 

They will get limited use, as many people don't even recognize the value of using one, and they will certainly be limited by the time of year.

I imagine myself getting into more rehab intensive (possibly even BRRRR) projects as I build my portfolio and experience!

Of course if there are different LP partners that will necessitate separate entities, even if the underlying assets themselves don't justify the need.

BiggerPockets also has a calculator you can use to analyze deals and I highly recommend you start this as soon as possible, even if you are not ready to buy.

They told me the same thing that I found in 2022 Texas Property Tax Assistance Property Classification Guide.