I would like to learn both of these languages. I heard that a Portugese speaking person can understand Spanish but a Spanish speaking person can't understand Portuguese that well. Should I study Portuguese first? Will it be easy to learn Spanish from there? I don't want to learn both at the same time, I think I would become confused.

Just wondering if anyone has had experience in learning a new language, particularly the ones I mentioned, and if so, what are the best courses I could start out with? I don't plan on only working with courses, I will eventually and hopefully move onto more technical ways of learning.

I have always heard that the BEST course, although expensive, is Rosetta Stone. True?

Also, I like the sound of the languages I mentioned, and they seem to be pretty useful and commonly spoken. But are these easy to "master" as a beginner? What would be, in your opinion, the easiest?

I am 20 years old, and although I suppose that is considered old for learning a new language, I would really like to broaden my horizons by taking on something likes this. How much harder do you think it will be for me? Any advice? Thanks!