Traveling by myself to Lisbon for just a few days - first time. I definitely want to spend time by the beach plus see the most important sights as well as enjoy some good food. A few non-touristy things could be fun too. I will be with some friends who live in Lisbon, so I thought it would be cool and unexpected if I offer an idea or two. Lastly, I won't have a car (unless I am with my friends), so I need to things that will be easy for me to get around. Tell me what to do with my time!