The amount of time it takes to join a band can vary greatly depending on the instrument, the genre of music, and the level of proficiency required by the band.
In general, it's recommended that you have a good understanding of your instrument and the ability to play basic chords or melodies before seeking out a band to join. This may take anywhere from a few months to a year or more, depending on how often you practice and how quickly you learn.
It's also important to note that joining a band requires more than just musical ability. You'll need to be able to work well with others, be reliable and committed to regular rehearsals and performances, and have a good attitude and willingness to learn and grow as a musician.
Ultimately, there's no set timeline for when you should join a band. It's important to focus on developing your skills and building your confidence as a musician, and when you feel ready to take the next step, start reaching out to local bands and musicians to see if there are any opportunities to join or collaborate.