I know you didn't ask for advice, but I'd say go for German.  You'd learn French in a flash.  You can learn French on the side, outside of school.  :)

I put a few corrections below, but I also want to point out one thing.  You are advanced with your English writing, so maybe now is the time to try using contractions more.  It sounds more natural.  For instance, in your message, you could have used "I'm", "I've", "I'd", "it's", and "that's".  You only want to avoid a lot of contractions if you're writing for business reasons or for some other formal reason.

My university, my future and me learning new languages.

I am studying for two careers. One of them is modern languages. I have been studying English since I started basic school, but now at the university, I have to choose between French and German in order to be able to talk speak three languages: Spanish (my native language), English, and French or German. I am not quite sure about [it's okay to say "about" here, but it looks better to take it out] which one should I I should choose. Last summer I had been studying French. I think it is similar to Spanish and that is why it was easy for me. I liked it. My boyfriend is studying German but I think it is more difficult and it is not so as helpful as French around the world. I still have time to think about it and to make my decision.