I feel like a lot of people are going to come and give you better advice than I can and I don’t exactly know your starting point on the language journey but yes, I think grammar is a good way to start alongside WK. You’ll be learning kanji and vocab through WK and if you go the textbook route you’ll learn grammar and vocab. Formal, independent study is a whole whirlwind though so starting off with Tae Kim, TokiniAndy, or even Sakubi could be a good jumping off point too.
There are so many secondary resources that I can’t list them all and I sure as well don’t know them all. I’ve been on the attempt to learn this language actively for 5 years now and everyone’s goal is different. I think setting strict short-term and long-term deadlines and defining your goals with the language is important because it’s a lifelong journey if you truly want to master it.
Lots of people (myself included) post study logs. They usually list their resources in the top post and comment on what’s working and not working. Browsing the forum for those and additional resources people use (like this Ultimate List) can help you settle into what personally works for you.
Just be open to not knowing things and constantly looking for translations and enjoy the ride. Don’t know what else to say except good luck! 