I’d recommend the double check script so you can re-do typos. Also, I promise you that WK speeds up after about 5 levels, then you’ll suddenly find yourself with a ton of reviews and lessons. It really does just take a bit of patience.
What I did for the first few levels when I was bored was use Kanjigarden, another Kanji-learning app very similar to wanikani, which has a free trial of 3 weeks, and the trial lasts about as long as it takes for WK to speed up. Learn as many kanji as you want on there. By the time you get to them in wanikani, you’ll be able to breeze through them. Once the trial ran out for me, I was getting so many lessons in WK that I had no need to learn kanji anywhere else. And the kanji I learned in KG really made WK easier.
You may even like KG more since you can learn as many kanji as you want, but you’ll still have to wait in between reviews since that’s how SRS works. You won’t learn vocab on there though. I mainly just used it to keep me occupied during the first few levels of WK. You could also check out grammar resources in the meantime, or try some listening practice. It’s never too early to start with either of those things, in my opinion.