For spoken language, perhaps there are audio courses you can try out.

I only know of the Michel Thomas Japanese course, but as it's not actually taught by Michel himself I don't know if it lives up to the quality that his own courses had.

The way I've started almost all the languages I've practiced is by combining an audio course with Duolingo (both are easy, fun methods used while commuting to/from work). This is a good way to get started, if you're finding it overwhelming or in anyway getting demotivated by the task ahead of you.

If you're already highly motivated, you should include the more "boring" stuff like course books and grammar books already from the beginning.

The first thing is learning to read and write katakana and hiragana.

After that, maybe consider getting some textbooks. The Genki series and "dictionary of basic japanese grammar" did the trick for me atleast and is a series I would highly recommend because when you finish it, you will have a basic understanding of the language and a strong foundation to build upon.

Other than that, ANKI is a really good non-gimmicky app for spaced repetition.

Naturally you would also involve yourself with different media in the targeted language that your are trying to learn.