When visiting Goa remember it has a rather harsh sun most days. So carry all your gels and suntan creams and your shades and even umbrellas and hats. If you forget them not to worry you can buy it in a shop nearby but do plan some form of protection from the sun.
A good thing to remeber is that some of Goa's beaches have loads of live Crustaceans and Mollusks [animals that have shells]. So do carry water proof sandals if you find crushing them under your feet a bit creepy. That comes with the unpolluted beaches of Goa. However fear not there are many beaches, especiallty the busy ones that do not have any live creatures crawling in the water bed near the beach.