Disclaimer: I’m not prioritising speaking, I’ve been focusing on reading.
TL;DR grammar and wider vocab. Kaniwani will help produce Wanikani words, but that won’t be enough alone to help you with producing Japanese sentences.
Wanikani is great but it’s primary goal is teaching you kanji and their reading, so many of the words are included just to teach those readings, in top of that there’s lots of super important words which are kana only, and other important words you won’t see until quite late into Wanikani.
Kaniwani is a great tool if you want to practice producing the words from English prompts, but that’s still only the vocab you’ve learned in Wanikani which is a subset of the vocab you’ll want to learn.
So based on what you’ve said I’m not sure if kaniwani is the best fit for you right now, given that you want to learn to speak and form sentences as neither kaniwani nor Wanikani will cover things like particle usage, and Wanikani doesn’t teach all the common verbs at the start.
I think you’ll want to try learn some more common vocab including verbs and grammar including particle.
If textbooks work for you then you may want to consider picking one up, they didn’t work for me as I find them a bit tedious but others swear by them and make good progress.
There are also free online resources for grammar like Cure Dolly (YouTube), Japanese Ammo with Miss (YouTube), and Tae Kim (popular online grammar guide).
I’ve been focusing on reading, +1 to mention of the ABBC once you’ve got some more grammar under your belt.
I’ve had a lot of benefit from making my own Anki decks, and in those I included a bunch of the JLPT-N5 vocab and vocab from Genki (common textbook). I’d previously read most of the way through the first Genki book before deciding it wasn’t working for me personally.
I’ll try edit this post later on to add links, just on mobile now.