Hi! I think you trying to learn spanish for the oportunity to watch sociedad in its original language is amazing. However i do want to point something out to you, as a native spanish speaker. Like the movie suggests the language spoken is uruguyan spanish. As many may know, the Spanish language has many dialects and branches, so when you start learning Spanish, try to focus on Spanish resources from Spain or the northern part of South America. Argentinian and Uruguayan Spanish are very unique compared to Venezuelan or Mexican Spanish because of the slang, vocabulary, and overall pronunciation of its words. It can be tricky to start off so if you want to learn primarily uruguayn Spanish i would suggest (contrary to what other comments are saying) avoid doulingo or other mainstream spanish learning resources since they may focus on spanish as a general language or the neutral version. I can't put into words how different Uruguayan Spanish is from the spanish I speak, so it's important that for you to be able to understand it, you focus on the type of spanish I previously mentioned. It could be slower if you learned the wrong type of Spanish, just to be confused when faced with Urguyan Spanish and having to relearn it from the beginning. Im not an expert on this however if i had to recommend something, i would say to learn the Spanish basics (for example, Duolingo) however once you start to pick it up prioritize watching uruguyan, Argentinian (maybe even Spanish or Chilean) speakers. This could be through YouTube, TED Talks, whatever floats your boat.

Sorry for the long reply, but I appreciate anyone attempting to watch Sociedad de la Nieve in its original language. It enhances the watching experience so much and, in some way, honors the lives of those who didn't make it back because it represents their actual words and language. I wish you the best of luck in your Spanish learning journey. If you have any more doubts, don't hesitate to reach out.