When I was 22, I did a house hack, and I highly recommend it.

It can eat into your cash flow, but if you're earning high income from your W-2 job (I assume you are if you're buying in all cash), it makes more sense to use your time making more income versus managing maintenance requests as you scale. 

If you start a JV in name but do not give your partners proper control and decision-making rights and the deal goes bad you open yourself up to serious consequences which can lead to SEC violations with extremely high fines.Lastly, you can offer the project up to investors who have no voting or control.  

I want to go the buy-and-hold route, and I am interested in finding a duplex that will provide a steady cash flow, a high appreciation value and does not need renovations.

And for sure I highly doubt those that teach the common wholesaling techinques are not up to speed with all these new laws in all the different states..

I wanted to share my situation and get some advice.I currently own an apartment in a highly developing area in Guaynabo, PR.

The owner said he would sell but at a very high price.

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

prices are high, interest rates are high, there is tremendous demand for inventory, and - one thing that doesn't get mentioned enough - a record number of properties are debt free. 

That looks to me like $200-300 too high for the current rental market.