Chances of entering MS Journalism at Columbia?

Hey there!
So I’m a 24 year old from Rio, Brazil, with a BA in International Relations from a considered good college (IBMEC), with a medium GPA (here in Brazil the scores go from 0-10, mine was around 6.5 ish, which might be equal to 3.0 in the USA perhaps). I never done anything related directly with journalism, but I have a seminar producing company, which has done several debates and events with the some of the best economists and intellectuals of the country. I had to interview a lot of people to convince each one of them to be part of the debates we organized, PRO BONO I might add, and succeeded. I which to become an economics reporting journalist, and because of my age, I thought of going to a Masters instead of doing another BA in Communication here in Brazil.
At their website, the Columbia Journalism admission states that no experience is needed in the field for the applicant, so I figured I’d give it a shot. I have done a lot of incredible things, but not in Broadcasting or Newspaper per say, but I have really good executive skills and I write a blog (which is not big, but occasionally some texts have been quite looked up) on daily news about the city and national news. I was also accepted for an internship at the Financial Times in London, but they at the last minute realized that I could never be hired because they couldn’t accept an international applicant (they overlooked this fact maybe because of lapse of communication, but maybe also because they thought my CV was really, really good). I really want to become an incredible professional, and I feel Columbia might help give me the skills.
Am I dreaming too high? What other schools should I look up? I thought of NYU and Columbia (really wanted to be in NY), and one of the best journalist of the country told me Columbia is the best. But I would also consider London, for example. If you guys could help me out, that would be great. Thanks!