You are really close Sara and Spain is not that different than Portugal, for me the major difference is the food, I think our cuisine is tastier and healthier than the Spanish one.Portugal is an amazing country, full of culture and beautiful landscapes, towns and villages.
Lisbon is definitely a highlight, with it's unique atmosphere. Some people I know actually think Lisbon is ugly because of the 'old run-down buildings' - they couldn't be more wrong in my opinion.