>>432523Surprisingly, what that anon is trying to lead you to is a guide to learning Japanese. Here, let me link you the site that's in the OP of that thread, since that anon was so unkind as to not do it himself:
https://djtguide.neocities.org/There, you will be able to get a lot of information on how you can start on your path to learning Japanese.
And the answer to your question is that you have to learn all of them. Hiragana and Katakana (The Kana) are the Japanese alphabet, essentially. Hiragana is used everywhere while Katakana is used for specific things, usually onomatopoeia or foreign words. While Kanji is used for nouns, names, concepts, etc. And if you're not playing a kids game, you're going to see all three at use throughout the whole game.
Thus, you have to learn everything.
