First thing you gotta think about is what your goals are. Conversational fluent speaking? Listening? Reading, writing? In my opinion a language should never be learned without being able to read it's writing system, but the focus depends on your goals. Writing could be pretty much unnecesseary to you.
One tip: Immersion. Learn the characters, learn the grammar, learn the vocabulary(!) but don't forget that it will be MUCH easier to remember and have the language become second nature, when you immerse yourself in it. That means watching japanese media, reading books, playing games etc. Obviously there needs to be some groundwork for that to be fruitful.
I assume you want to learn the language out of your own interest so another tip from me is to not worry about difficulty too much.
I have some.other stuff I can say, I'll come back to this when I get home