@Xavier Perera If it’s financially feasible I suggest starting by house hacking a 4-plex. The cost shouldn’t be double what a duplex is, but should likely be less per unit.
The learning curve wasn't any bigger for my first 4-plex vs the SFH then subsequent duplex that I bought.
Where I got into my first big learning curve was when I bought my 8 unit, both in the increase in number of tenants and because it was a fixer upper with inherited tenants that had also been neglected and mismanaged for years.
I’d recommend starting with a property that needs little/cosmetic work that can be rented from day one, and preferably has existing tenants. That way you can hopefully do renovations as tenants move out one by one and start to build your network of contractors.
Once you’ve got a little experience under your belt then you can attempt buildings that need more renovations/repairs or have had management issues.
If you initially end up needing to raise rents I like to do them one at a time to minimize potential turnover from happening in multiple units at once.