Things to do in Porto Alegre during the weekends

It depends on your age group.  Lots of folks stroll by the Guaiba Estuary esplanade.

Also being invited to BBQ ( Churasqueada ) is a thing to do. 

Porto Alegrenses are very much into culture, so hitting artisan markets, museums,watching a play are a thing to do.

If sports is a thing, a Gre-Nal is a can't miss when it takes place.  It's an unmatched rivalry between Gremio PortoAlegrense and Sports Club Internacional .

Through the winter, visiting the Serra Gaucha for wine sampling is a thing to do. 

If you have a sweet tooth, Pelotas, by the Estuary is a place to go.  They have  lots of festivals for pastry and candy making there.

As cosmopolitan Porto Alegre might be there is a strong Agricultural heritage in the South, so getting the calendar for State Fairs, mostly held around a specific productive chain is a cool place to hang out.  Like a Feira do Vinho, or some fruit or dairy

Buy yourself a Mate bomba, you  will be exchange a lot of mate sipping sipping with Gauchos. 

One way to spot for places or events to go is to check on your local  chartered CTG or Centro de Tradicoes Gauchas.  They have places where locals meet to maintain local customs and heritage on food, dances, wardrobes.   Just google or duck go duck on "Centro de tradicoes gauchas  em porto alegre"

Good luck