>>1905You can learn kanji by doing vocab so it's already mostly down to only 2 things in terms of studying, ignoring the most important part being immersion of course.
I know some people shit on them a lot because it costs money and there's tons of great free resources so they're really not necessary, but I've had faster retention from (with third party scripts) speedrunning the wanikani* kanji course with their vocab (you can get their kanji+vocab deck in anki for free online if you don't wanna pay though I don't know when they were last updated). At max speed it takes roughly a bit over a year to learn 2000 kanji and a bunch of vocab as a side-effect. Roughly 40 kanji a week and 125 vocab a week all relating to the kanji if the previous week. It will slow you down if you don't do it right though. I'm sure some grinders can do faster, but with the usual anki decks I had way worse retention and ended up going slower than that.
For grammar I watched some cure dolly videos on youtube to get the absolute basic grammar down then just grabbed a bunch of grammar from bunpro* to get started. I found simply reading TaeKim's to be a lot slower because of lower retention for myself which just made it a headache, but I did read a fair bit of it. Bunpro's not perfect, but it gives a massive list of grammar to practice bit by bit which made reading a lot easier. Every sentence I see on their site I make sure to disable translations and make sure I understand the whole structure and meaning of the sentence myself and not just the single grammar point I'm practicing so I get regular reading practice of everything I know at an steady increasing more difficult level as well as practice for the current grammar point. I haven't tried their vocab, not sure if I even will.
I'll just grind the rest of missing kanji+vocab through sentences I mine from immersion later. That's when you really get to practice all three at the same time anyways.
*p2p/p2w - if it's convenient enough I don't mind paying to make my learning more efficient. I'll need to use mainly anki+immersion when I'm done with these though so I'll end up doing the same things everyone else are for free after a while.