First, I recommend you read this : http://guidetojapanese.org/learn/
it will give you the essentials and it's always a good place to refer yourself to when in doubt. Or when you want to understand some new grammtical concept.
Also read this : https://8020japanese.com/japanese-sentence-structure/
it's a really great explanation of the fundamental principle of japanese language.
This at least should give you an idea of how the language is. For serious daily learning, then, I use two things.
First is https://wanikani.com
It's a web app that aims to teach you the necessary kanji in life and a lot of vocabulary. It's immense work (been doing it for 2 years and only now reaching the end) but it's a necessity if you want to learn to read.
And then, a more rewarding one : https://bunpro.jp
Same principle as above, except focused on grammatical points. It's going to make you progress much faster than wanikani, but doesn't teach vocab.
Still, it will allow you to understand correctly the sentences you know the words of.
Not gonna lie, while it's not a partiuclarly hard language, it takes a lot of work.