I also started October last year! I began using Wanikani and Minna no Nihongo almost simultaneously and although I believe I’m progressing fairly quickly through the Wanikani levels, the progress still feels very slow. Meanwhile Minna no Nihongo has been doing wonders for me. It has everything a textbook needs: doesn’t use roomaji, has a lot of vocabulary, grammar explanations, dialogues, listening, reading and writing exercises, just the right amount of drills for every new grammatical structure, overviews and tests. Admittedly, I have never checked out any other grammar resources, but I never felt like I had to. I know that Minna no Nihongo is going to teach me everything I’ll need if I just stick with it until the end.
This is also why I’d always propose to pick one resource for grammar in which you can put your faith that it will teach you everything you want. Juggling between five different resources is going to make it so hard to progress, because you’re never actually reaching that state when you’re familiar with the structure of one and can comfortably, efficiently and quickly suck everything your resource teaches.
I wouldn’t recommend you to begin with the second book, though. Instead, I’d suggest you progress a little faster through the parts of the first book that teach what you already know. Doing all exercises in writing or skimming over the drills are two entirely different approaches as far as time investment goes, and you can perfectly do the latter to save yourself some time. But by skipping the first book, you’re going to miss a lot of vocabulary and grammar structures the second book requires you to know.
Finally, this is probably my most controversial take, but since you asked for Japanese resources for Japanese speakers: I personally don’t think it’s very effective to immerse yourself in native material before you acquire a respectable vocabulary, kanji and grammar knowledge. Immersion is not for studying, it’s for practicing, getting used to the language and becoming natural at it. The better you are when you start, the more useful it becomes. If you try to get in too early, it’s more strenuous than actually studying, it takes the time you could have used for studying, you miss most of what is said, and most importantly, it is incredibly disheartening. Learning a language takes a long time, and while jumping into immersion may feel satisfying at first because you’re ecstatic from being able to understand some parts, the more time you spend doing it, the higher your standards for yourself become, the less improvement you start to notice, and the more impatient you get. It’s like asking to get burnt out.
So in a nutshell, I’d suggest: Pick a grammar resource to accompany your Kanji studies in Wanikani, stick with it until the end, and finally you can surround yourself with material meant for native speakers.
EDIT: Didn’t realize my reply was that long until I submitted it, holy hell
