Before purchasing property in Brazil you need to decide if you want to use it as a permanent residency, a holiday home or for letting purposes.
If you intent to let the property look for a profitable region and housing types. These are not necessarily properties in touristy areas but can also be regular appartments for people working and living in Brazil.
The best thing to do is to start your search for real estate on the internet before coming to Brazil. This way you can already get an idea of the prices and the availability in the different regions. If you find something you like, wait until you arrrive in Brazil and view the properties in person. You must never make any arrangments in advance as there are many offered properties which do not really exist and are only meant to cheat naive foreigners.