moving to japan and develop your talking skill by talking? You need a solid foundation, to actually be able to improve by talking. And just being in Japan doesnt help at all. Yes, you can get alot of ressource, for example in a bookstore, but in terms of people, its not like they come at you, and offer japanese lesson for free and try to be your friends. Finding meaningful connection is much more unlikely in japan, and also depends on you on a person how social skilled, charasmatic, circumstance you are in. What i just said maybe comes off as pesimistic, but i just want to make clear, that just going to japan isnt automatically the bewst way.
If you don t intent to go to japan due to lack of money or time, i recommend learning useful phrases. You can extract words and grammar this way, which i find myself in alot. And after that, its basically repeating youself phrases, in therms of efficiency, i would say a japanese pod, in terms of my recommendation, anything that makes you keep practicing more and not drop it. I personally would recommend breaking down songs, translating and learning them since that could make alot of fun, if youre already a little bit more advanced.
If you go to japan, i recommend atleast:
-going to a language school.(i m currently at genkijacs and the student support is great)
-staying at a japanese homestay.
Both recommendation ensure a basic amount of social interaction with japanese people, which will be crucial if you find youself alone in japan.(me currently in summervacation lol)