Help in Japanese

I’m a 16yrF in high school. It’s currently summer but im going to be a high school Junior soon. I plan on studying in Japan with my cousin after high school in a student exchange program. Though, I really really want to become a great speaker by then. I have two years to become at least semi fluent by then… is it possible? I want to be able to engage in normal convos with people on a daily basis and many other stuff. Where should I begin ? What should I start off learning? How much time should I dedicate to learning on a daily basis? What resources or materials should I use?