Japanese!

I really recommend Renshuu.org! It’s both a website and an app! Renshuu is great because they have their own bite-sized grammar lessons, which is lacking in something like Duolingo. It also has a great community, cute art throughout the site, and rewards to keep you studying.

Its really great. Plus, its free!

Kanji

Read Japnese Today - Book on the Internet Archive about learning Kanji. It’s very illustrative and has drawings that relate to the kanji. I haven’t finished it but I heard it’s been very useful when starting out!

Jisho Radicals - Japanese dictionary website, but the direct link is great for learning about kanji you dont recognize. (Its also a really useful name dictionary for explaining the meanings of Japanese names.)

Other

Learn Natively - Great resource for finding Japanese media based on your learning level! Not only does it have manga, anime, etc, it also has textbooks and where to find them!

Yomitan - Dictionary for computer, you can press shift over Japanese words on browser for a definition, and sometimes even pronunciation.