Gaining language skills

Hello all, I am a second year IR and diplomacy student with a focus on security studies. I am American and only speak English (I know I know, typical monolingual American haha) but I live and study at an English-speaking university in Prague, Czech Republic. As I’ve been on this subreddit, I see that lots of people say that foreign language skills are highly beneficial for a career in this field. I have a very beginner level of Czech because I live there for right now, but I am totally open to learning any language that will prove beneficial for my career. My main question is for those of you who have learned a second language for career opportunities, how did you do this? Did a job provide training? Did you move and fully immerse yourself in the country of the language you are learning? I just want to hear how everyone here achieved a second language for work opportunities and how I can plan to learn a second language in the future. Thanks in advance for all the answers! Let me know if you have any clarifying questions.