There is no such thing as "the best time" to be at Porto, because this city is wonderful at any season.
Be sure to bring warm clothes!
We have two main means of transportation: bus and metro. Our metro system is quite big! It crosses the whole city and a good amount of buses.
The simplest ticket is the blue Andante card, which alows you to enter both Metro and Bus, plus lets you pay per journey. The key thing to know about this card is that it gives you access to all transports in town (even tram!) and you only need to charge it before using it.
Just remember: All cards must be validated every time you get on board, and at any change of vehicle.
Take a look at the Metro Map.
How to get to the venue