First, let's talk about strategy and when to learn what part of Japanese. Wanikani's knowledge guide section on prerequisites says that you can immediately start learning radicals, but it's useful to know Hiragana before learning your first Kanji, and to know Katakana before learning (slightly) more advanced Kanji. Note that the emphasis here is on _reading_ Japanese. Not listening or speaking. But we can derive from that an order for learning to read:

1. Radicals
2. Hiragana
3. First level of Kanji
4. Comprehensible Reading Input
5. Katakana
6. Remaining Kanji

But let's try to build a path for learning listening/speaking as well. The general consensus is that romaji is harmful for learning Japanese pronunciation, mainly because it's misleading. So it would seem helpful to learn Hiragana and how each character is pronounced before exposing yourself to comprehensible input, in order to think about what you're hearing in terms of the hiragana. So here's the order for listening/speaking:

1. Hiragana
2. Comprehensible Listening Input

Altogether, this suggests that Hiragana should be first, and then there should be 2 parallel streams: reading and listening.

• Tofugu Guide to Hiragana
• Tofugu Guide to Katakana
• Wanikani Guide to Typing Japanese

• Kana (Hiragana, Katakana) Quiz
• Real Kana
• Comprehensible Japanese Input
• Wanikani (Radicals, Kanji, Vocab)
• SRS with self-made mnemonics

• Video: Tips for input