Get going from the sofa! Contact your trusted realtor through the real estate portals that will help you define the criteria for your search [area, price, size ...].
We start with the search for your apartment through your trusted real estate agency, or the real estate portals. Knowing what you are looking for, what area and what budget you have, this process will be more fruitful for you. Consider expanding the search criteria if there is very little supply of what you are initially looking for.
Once you are clear what you are looking for as well as the available documentation, you should start the search in the real estate agencies you trust, so that they can inform you of their portfolio or possible apartments that will enter them.
They are the ones that can best advise you. If you can't find it through your contacts, you should use the reference real estate portals. In most portals there is the option of creating alerts based on filters, defining what you are looking for, so that as soon as a flat that meets your requirements is uploaded, they will notify you as quickly as possible. Contact the advertiser and ask how to proceed to choose to see the apartment, with the intention, if it fits within your search criteria, of keeping it.