A nice way to build bridges to your local community is to create partnerships with cafés and restaurants. They can perhaps offer a discount or a free drink/dessert and in return you can promote their restaurant to your guests and in your hostel.
This is for example done at Albergue do Praia do Forte Hostel and Aju Hostel & Pousada. Agree how the guests can prove to the restaurant that they are staying in the hostel. This can for example be to show their booking confirmation on email or by bringing a card from the hostel with the guest’s name and dates for the stay.