Hi! I was just there and used the KubikTrip website to plan everything. Their Porto city guide is super helpful and easy to follow. For the hills, just use the metro and those cute old trams - they save your legs a lot! You definitely have to try a bifana and some local port wine in Gaia; the flavors are amazing. According to the guide, the city has a high safety rating, and I felt totally fine walking by the river after dark. It’s a beautiful place with great vibes, so just relax and enjoy the views from the bridge. Have a great trip!