I’m just starting off, and wanted a few people who have used wanikani longer then I have to give some input. The problem that I’m running into is that some of the kanji and radicals I’ve achieved guru with, are starting to become hard to recall the readings, due to all the vocab with different readings with kun’yomi I’ve been doing. I’m not sure if I should do some sort of review, or just wait for those to show up in a review and see if I’m able to recall them. I’ve also purchased a kids manga that I should be receiving in a month or so, to work on reading actual material and figuring out the words and whatnot. If more experienced users could give their input, I’d appreciate it.
I’d say just keep doing wanikani, read as much as you can outside of wanikani and write as much as you can (texting or whatever is fine). It’s about using what you are learning and seeing it in many different places.
Some readings will stick, and some won’t. With WK’s system, you’ll keep getting the ones that you struggle with until you finally get them.
There’s also the self-study userscript that I’ve used when I seem to hit a wall. You need a userscript extension for your browser to install it if you choose (Greasemonkey for FireFox, TamperMonkey for Chrome).
If you’re just starting with Japanese, then the short answer is that you’ll get used to how the differences tend to sound. せい、しょう、vs かわ、うけ, etc. Using other study materials in place of or alongside WK will help your exposure.
A rule of thumb is that compound words tend to use the on’yomi, which is fortunately the reading you learn often with the kanji. Single kanji words or words with kana trailing off the kanji tend to be kun’yomi and whose readings are introduced with that vocab word.
白人 (はくじん) - on’yomi. This is a compound where two kanji are smashed together to make a word.
大いに （おおいに） - kun’yumi. This is a kanji with trailing kana.
These rules aren’t bullet proof. But take heart, the first few levels’ readings seem to be more irregular than later levels because there are a lot of kun’yomi heavy readings in the vocab.