yesmate,
i surfed in lagos in october 08 with extreme holidays (now bust) and had one of the best surf hols ever, at the time i was at the same level your at and even then the waves werent too challenging, the biggest days were about 3-4 ft at the beach breaks and had decent wedge shape, but you can find some more challenging waves if you feel like pushing it and exploring. however pretty much all the decent breaks were a 30min to 1 hr drive to get to so maybe consider a surfari, most of the surf camps there will provide transport to the local waves and will go to the spots that suit the group.
i also stayed at baleal surf camp in penice, further north about an hour from lisbon and again they had great waves for all levels and a great location right on the beach. i tend to visit portugal in the autumn when the swells a little bigger but the summer should be fun too and definately good for your level. just bear in mind that lagos is a big party town and very busy in the summer and often very crowded on the waves.
hope that helps....oh and in lagos, visit joes garage to start your nights out!
