Fuez

Don't simply read through a grammar guide, you should make notes for everything to quickly refer to them later (plus it stimulates your memory as you write it down). DO NOT learn vocab using JLPT N's, aside from N5 and N4 just to get you started, unless you specifically need a JLPT certificate for something. You should read untranslated material (without machine translation), no matter how slow it goes at first, and add words you find to your vocabulary. You can use Memrise or Anki for that, as they would be very helpful in revising those words in a way that you don't spend too much time on those you remember and spend enough time with those you struggle. I personally would recommend grinding 2000 kanji in heaps before any vocab as that would let you overcome the biggest wall, but if you don't want to bother with that then simply use some program that adds furigana to text (idk which one to suggest, I've never used one but I think VNR does that).
Never, ever use machine translation.