I recently recited Japanese letters on https://www.nhk.or.jp/lesson/en/letters/hiragana.html, which took me 10 days. And I now know hiragana and katakana very well. Next, there is a website https://jlptsensei.com/complete-jlpt-grammar-list/ on which I will study over 1,900 individual kanji characters. And I will also read the book ‘Japanese from Zero’, which has more than 3,000 pages.