How much time do i need to put into my banjo playing each day?
That’s not for me to answer, but you. The more time you spend (IF you spend it well), the better you will get, faster. You can figure out how that works for you. If you want to get noticeably better in a year, try practicing an hour a day. I recommend focused, goal-oriented practice blended with just enjoying yourself. Please read my instructional materials for ideas on what’s the most productive way to practice, and what will bring the best results. Carelessly guided practice doesn’t bring the results that smart practicing does.