Hi!
For grammar and conjugations, many people recommend BunPro.jp - it’s an SRS system similar to WaniKani that runs you through grammar points and lets you practice them against multiple example sentences. If you’ve done some learning of them and want some variable difficulty questions, you can try https://katsu.arthurhoek.nl which is a conjugation practice tool 
Aside from all that, since this is your first post…
\textcolor{pink}{\huge \textsf{WELCOME! ^-^}}
Take the time to check out the FAQ and GUIDE if you haven’t already.
There’s also a lot of good stuff on the forum to help you, like:
The Ultimate Guide for WK
The Ultimate Additional Japanese Resources List!
The New And Improved List Of API and Third Party Apps
I hope your Japanese learning journey goes well and that you enjoy your time with us on the forums.