Japan is a very interesting country with a long history, and an even longer list of works of art ranging from literature to film. I became interested in learning Japanese when I started watching Japanese cinema, and sadly a lot of it remains completely untranslated (or even worse, mistranslated) to this day. Thus began my journey into a hackish DIY of appreciating films that evolved into (so far attempts of) reading literature. Everyone might have different goals, of course, but if you find yourself here, then I assume some interest in learning the language.
This is going to be less of an instructional thing, and more of a personal collection of experiences - what works for me, what doesn't, and what is vital to learning the language. I am going to give as much freely available material as possible here. Considering the multitude of online resources when it comes to learning Japanese, some would argue you need a guide for picking a Japanese learning guide. I'm strictly using my own hacks and workarounds ,but at times I will point to other techniques that I ignored, and give reasons for doing so. You might disagree, and branch off to different methods. That is for the best, and I strongly urge you to do so.
What should be stressed most of all, is this is going to be a very long process. It will take most people years to acquire a basic understanding of the language and its vocabulary, and depending on what path you follow, you might be none the wiser of how to speak or comprehend even the most basic sentences after months of effort - in my opinion, that is the way to go, as it will give you a more solid foundation.
I also stress that this is purely a hobby to me, and any of the advice shared here taken as anything more than advice, is at your own risk of wasted time.
The writing system, all three of it
As hopefully evident, you and me both will have to go through learning three different writing systems. Let's go through them:
This is the official Japanese phonetic alphabet, consisting of 48 characters (including 2 that are no longer used). Each character represents a different syllable, and obviously not all sounds are covered
The phonetic alphabet used for words derived from other languages, such as 'hamburger'. Also consists of a total of 48 characters (including 3 that are no longer used). It looks and feels simpler than hiragana, and also serves a purpose of modernizing specific aspects of Japanese (mostly sounds not included in the original alphabet).
The pictographic alphabet, and effectively what keeps Japanese from being a relatively easy-to-learn language such as English. Many of the characters here represent either a word, or part of a word. They have usually at least two different readings each (which situationally change). On the average everyday situation, you would expect to run into ~3,000 of them, a fraction of a total 50,000+ characters.