Bowling leagues are fun. When I was a young man, I made many friends bowling, later I was able to tell them about Jesus Christ. But perhaps you don’t like bowling, well it doesn’t matter what sport you like. The point is to join a Sport and later when people become your friends tell them about Jesus the only one who won’t cheat in order to win their souls.
It is OK to have fun, and even join a sports league but just remember you are not there to become a world class athlete or to win championships at any cost; your primary objective should be to win souls for Jesus. Go ahead and play, but also pray.