If you want to learn a little Portuguese prior to coming to Portugal, follow these instructions for some basic Portuguese lessons on YouTube:
(Always check that the lessons are not in Brazilian Portuguese, as it is different from European Portuguese)
1. You Tube: Follow these two short free courses (it is a selection of videos)
2. Italki
One to one classes with teachers on Skype. This is the method that we use and we can recommend a very good teacher to you. Sign up to italk via the link below and when you book a lesson receive free credits due to the referal program:
Otherwise get yourself over here and practice in the cafes!