Public transportation, such as buses and metro, is widely available in Porto and affordable. Taxis and Ubers are also available, but can be more expensive. For day trips, consider renting a car or booking a guided tour for convenience. Keep in mind that parking can be limited and narrow winding roads may be challenging to navigate.
If you have more time, consider adding an extra day trip to the beautiful region of Douro Internacional National Park. If you have less time, consider skipping the day trip to Braga or Douro Valley.