>>23423182I'd suggest you take take a language school that works like an actual 9-3/5 school, if you can have a leeway on your work schedule.
But for starter, learn kana and then basic grammar rules (don't jump to -ます forms, always start with plain forms) with textbooks like Genki or Minna no Nihongo; personally I prefer the latter. Then watch, listen, read, and review as many Japanese stuff you're learning and like along the way.
Take some JLPT test questions once you reach a point where you feel comfortable reading something, no matter how easy they are
