Problem Installing Script

Hey Guys, I've followed the steps carefully in downloading and installing radiodj. Also in successfully installed Mysql Server 8.0.11. I have entered i password and everything but it won't validate. It keeps telling me Mysql Server Is Offline and also showing this error : "Authentication method 'caching_sha2_password' not supported by any of the available plugins" What does that mean? and What should i do to fix this?