Social life is very important to the people of the villages in rural Portugal. Most of the villages have an association (associação) where they come together every weekend and drink a vinho or play card games. You can become a member of this association by paying a small fee (like 8 euros a year for example) It depends on the size of the village but they normally organize lunches, parties and walks during the year.
You can also go to the local café every day for your morning coffee or afternoon drink and you will meet more people. If you reach out to them, they can become a great friend who is always ready and willing to help you with whatever you need.
If you are not here with the intention of building a social life, that is fine. The Portuguese are generally very respectful and they will soon understand that you appreciate your privacy.