I (re-)started learning Japanese again after a 20 year break, from when I had it in school. I tried Duolingo for a month, but I grew frustrated with the new design and how it assumed you should know stuff - which was explained afterwards. I ordered Genki (a textbook) and started learning with Wanikani, and that really worked for me. I like the SRS system, and am trying to get into Japanese books by now. (edit: doing WK for ~6months, 2x daily)

This is what worked for me - it doesn't necessarily will work for you. Just shop around and see what you like (eg: paid instructor, online learning, textbooks) and can stick to. Then it's only a matter of time until you pick up the language.