Which one of these slavic languages should I start learning (and why)?
I narrowed it down to these four languages that seem to appeal to me the most. If it helps you decide, I'm a native European Spanish speaker, fluent in English, almost fluent in French and learning German, Italian, Norwegian and Levantine Arabic.
I'm interested in a language most intelligible with languages from the same family (slavic), and from a country with a rich and open culture. It doesn't matter to me whether the country is small or has little population, but I would prefer a language that I could learn for free or for little money, so no expensive online tutors (I would love to interact with natives but I just can't afford it).
Thank you in advance for your time! :)