Hi
Imo, if you are serious about learning Japanaese you hould learn Hiragana and Katakana
before starting any course or learning vocab.
You can use the Kantan Kana videos on this site. You can learn the vocab given there, or ignore it, doesn't matter.
Learning Hiragana and Katakana should take you somewhat from 1-6 weeks depending on how much time you can spare and how fast you can learn.
If you have that down start with the Absolute Beginner Series and from there follow the Nihongo Dojo Series. Find a very good Overview for this Series here:
viewtopic.php?f=2&t=7235&p=39937&hilit=lesson+order#p39937While you are still in the Absolute Beginner level you should stick to Absolute Beginner Level Courses, cause the rest can sometimes be overwhelming (the sole exception here would be Beginner Series 1, cause its about Newbie Season Level).
I recommend watching the Kanji Video Series with Hiroko and the Grammar Series Videos (they give you a good explanation of basic grammar and are very helpful for reviewing stuff)
Once you are a good way in the Beginner Level you can start to explore a bit more, and listen to Intermediate Level courses and so on.
My very own special tip for you ^^: use the note taking function in the lessons. Write down if you have trouble understanding smth, what grammar point was discussed in this lessons and possible reference lessons, it will help immensely in the long run and when you come back to review.
Go by your own pace. Its tempting to do a lesson per day and go very fast through the lessons. Don't do it. Take your time, and make sure you did understand what has been talked in about in each lesson. Absolute Beginner Series and Newbie Series + Beginner Season 4 are extremely important here, cause you get a good deal of grammar. So this will be your base knowledge. Make sure to get it down. It will pay off in the intermediate courses, trust me i know what im speaking of
If you have any question you can pm me or just ask in this thread, Im happy to help out any time.
Regards.