How to use this guide and Learn Japanese
Basically, this guide is a primer. This guide takes a very specific stance: The only way to acquire language features and become fluent is to consume them in a real context. This guide doesn't try to drill you, and that's a good thing.
When you read this guide, don't try to memorize it. It won't work.
You shouldn't spend a week on each lesson. In fact, I think one new lesson a day is far too slow, even if you're also reviewing old lessons.
Every single main lesson in this guide covers basic grammar. You should read the entire thing as quickly as possible. It's important to get stuff in your head sooner rather than later. It gives it time to grow, subconsciously, and even if you didn't feel like you learned it the first time, it makes it easier to remember it for good next time. Just don't get stuck reviewing it forever.
After you get far enough in this guide, you should start trying to read.
Trying to read on a regular basis, even if you can't do it for more than five minutes, tells you exactly what your weak points are, and gives you a sense of progress. This guide exposes you to grammar to let you parse things, but you need to consume real japanese to turn that exposure into acquisition.
The most efficient way to learn vocabulary is to start picking up words from media you enjoy, then memorize them with flashcards. This is called mining. Anki is the recommended flashcard program because it uses Spaced Repetition, which shows you stuff less often the better you know it. You can use frequency lists or shared decks prepared by other people if you don't want to mine.
If you want to speak japanese, you must consume audible spoken japanese, otherwise you'll sound unnatural. It doesn't matter if it's anime or news or living in japan, you just have to consume it in the spoken unwritten form. This can come after you learn how to read, but you should passively expose yourself to it (with anything: VNs, music, anime, etc) as early as possible, otherwise it'll take a long time for your brain to pick up on nuanced sound differences, like how japanese people need to be trained before they can tell apart L and R.