To be honest there is no perfect way to learn Japanese it's the same as with every other language. The probably "easiest" and for most people best way to learn a language is to simply visit a language course. You might wanna inform yourself maybe there is a Japanese language course in your town or at least close by if not then there is the option (if you have the money and time that is) to go to Japan and visit a language school there. Or you could also take lessons here on italki. Also, self-studying isn't inherently bad. YouTube videos can be more than just valuable if you are studying by yourself but you shouldn't rely only on YouTube videos you should see them more as assistance. Best thing would be to buy a book for example and study for yourself. Also, try to always ask or research if you are having issues or are not understanding something. Just ask the italki community for example.