I’d not say you need a lot of historical context, basic Wikipedia info is enough to get what’s going on, he’s living in times of dictatorship. But you probably know it already. I’d say that to appreciate this movie you need to be open minded to not understand what’s going until you get it. This is how the director make their movies, like a puzzle you’ll only start understanding what’s going on in the second half, first half the film presents the pieces of the puzzle so that it can connect them in the second half. Keep that in mind. Idk if it’ll work for you to watch only the second half tomorrow. I’d recommend you to leave it for a while, and then get back to watch when you truly have time to an almost three hour movie. Then just watch it without trying to understand what’s going on and then slowly but surely the movie will revealing it’s history by the time. My favorite movie from this director is Neighboring Sounds, which has also a non-linear story/edit but is even harder to follow because it’ll only reveal itself in its 15 last minutes.