It is difficult to talk about learning tools, as learning methods are not the same for everybody. First of all, mind that you don't learn a new language as you would learn calculus or a programming language. Some people argue that learning the roots of words is the best way to learn. There is also those who believe that learning useful phrases is the way to the language. But, after all, it doesn't hurt to use everything that you can to get used to a language.

First, let's separate two concepts: Learning and Memorisation; they are not the same. Memorisation is about remembering, learning is about knowing to use. You can memorize a complete list of numbers, without knowing anything about them. That is what a lot of sites do, giving you vocabulary without teaching you on how to use it. Without the power of interpretation, you won't survive a real situation that you have to use the language. That is what learning is about.

Well, but learning without memorization... What we are after is equilibrium.

The Japanese writing system comes in three parts: Hiragana, Katakana, and Kanji. There are 46 Hiragana characters, 48 Katakana characters, and 2,136 jōyō kanji, that is a Kanji list specified by the government, but we will assume 6,355 Kanjis, that is the number of Kanjis tested on the last level of the Kanji Kentei. How do you learn that?

Let's get started!

It's important to you first learn the Hiragana(平仮名, ひらがな), that is one of the japanese syllabary. You'll use the Hiragana to write particles, furigana, to conjugate and replace kanjis.

You can click the Hiragana to hear how it sounds. All of the sounds have been taken from: https://soundoftext.com/.

External:

I would recommend you to take a look at the JapanesePod101 Hiragana playlist, there you will learn the stroke order and some words.