As others have said in this thread, WK won’t teach you Japanese on its own; you will need a path to follow.
I recommend, when you want to start in on grammar, find a book like GENKI, TaeKim, IMABI, etc and start.
If you like the SRS method, check out BunPro. It does SRS for grammar like WK does for kanji. In this case, check out BunPro, see if you like it. If you do and want to invest in that tool, I very highly recommend you choose a “path” they have available to follow and use that book/online resource to learn grammar, using BunPro to stick it in your noggin’ like WK does kanji.
There is also
BunPo that is similar to BunPro, however it doesn’t have a web version, only apps on Android and iOS.
You should also troll through this thread for next steps as well!
And as always, if you have any questions we are all here to help!