My two cents on the grammar vs vocab argument: early on, learning vocabulary is far more important. Imagine you’re a beginner who’s trying to learn about の, and an example you’re given is 英語の雑誌 but you have no idea what either 英語 or 雑誌 means. How well will you really understand simple grammar points when you don’t know any of the nouns, verbs, or adjectives around which the grammar is operating?
This is why the tofugu official Learn Japanese guide Learn Japanese: A Ridiculously Detailed Guide suggests getting to level 10 on wanikani before even touching a grammar textbook like genki 1. If こういち and the folks at tofugu are smart enough to put together wanikani, I’ll gladly trust their advice on grammar.
I am only at level 5 but I come from RTK (which is another method, similar, based on mnemonics, it has been widely discussed here) and years of Japanese study so I guess I am pretty experienced, overrall, with studying Japanese and frustrations that you will encounter.
What I recommend to help memorize very quickly is to focus on the mnemonics which are an incredibly powerful tool for many people. WK uses mnemonics but in my opinion it doesn’t guide you through it very well (as RTK does): you have like to completely shift the way you have always studied and used your memory.
Mnemonics will help you a great deal, if what WK suggests doesn’t work try to figure out new ones, best if they are weird. Take your time, imagine and the image will stick. It can be very quick.
If a Kanji or a radical gives you a lot of trouble try to learn to write it. You won’t find resources about it in WK but you can try apps such as kanji tree or, better, Japanese app (you can make custom lists) as you will need to write them in the right way.
I never said it didn’t. I even specifically mention that:
Knowing kanji greatly improves being able to actually read the sentences in that guide because otherwise you are constantly looking up words at the start of a section due to a lack of vocabulary base.
Again, as my full post states, it makes using his guide much easier when you actually know the kanji. Never said you couldn’t use it without knowing kanji.
And it’s not like I just made this up out of whole cloth. Even the WaniKani faq mentions it’s better to start studying grammar after building up some knowledge of kanji and vocab.
When I was starting out on Japanese in university I definitely do remember having a harder time grasping the grammar points when I fell behind on vocabulary. It was hard to focus on grammatical learning when I was constantly thinking to myself what the nouns, verbs, adjectives etc that composed a sentence meant. Vocabulary is pretty much the most time-consuming part of learning a new language (and definitely one of the most important), and it’s never too early or too late in your journey to do vocab study.