I have only been to Lisbon, Belem, Oeiras where my host family was and Cabo da Roca but I suggest you visit all these places. I got free tickets for a football match (Belenenses vs Vitoria Guimaraes) last time I went there so see if that is an option. If you need to get around Europe with cheap tickets, by the way, I wrote this post that can help you https://steemit.com/travel/@borderedge/how-to-find-the-cheapest-flights-from-anywhere