I learned Japanese through a Community College course, and I think it was the best method. I was fortunate to find a summer class that met four days a week for 4 hours each day, which was perfect. Immersing yourself in a language is always the best way to learn it, so no matter which method you choose, do it often and do it all the way, don't half ass it. If you can find others to learn with, that's even better. You'll always help each other out and you can be sure that no one's judging you since everyone's still learning. Bonus for you if you can find a native speaker to join you and a professional setting such as a school might be the best way to find that. I know the college I went to offered native speakers credits or something along the lines to get native speakers to help out the students either in class or as tutors.