Joao has a great appartement that has all you need and I mean everything! Bedlinnen, towels, a first aid kit, spare clothes, basic food items...and even a PS3 :) Heck, it even has 2 bathrooms!
Once there you'll only need to buy groceries (and even then there were basics at his place like salt, sugar, coffee, toilet paper, etc). Both supermarkets are a 2 min walk away. Next door there is great BBQ restaurant which is awfully cheap and a bit further into the street there is a great coffeehouse which is even cheaper :)))
On arrival Joao even let us in earlier! Only 30 minutes after our plane landed we were welcomed into his place where he gave us a tour and provided us with all the basic whereabouts of the neighbourhood.
Even his neighbour is a great guy! He printed our return flight tickets, handed us a spare key and opened the door for us downstairs on our way back to the airport (always check if the door is open downstairs before leaving the keys on your departure :) )
The beach is a 10-15 min walk. The city of Porto is a 30-40 min trip. We took the bus and then the metro which drops you off right in the centrum. A tourist ticket cost us 15 EUR with which you can the bus/metro freely for 72 hours (highly advised because you'll go crazy with all different zones).
So if you decide to go to Porto but you'd also like to relax a day or two at the beach this is the perfect spot!