How can i change avatar warning level reputation... that box to be on left side not on top?
UCP > Edit Options > find the box on the right about the classic postbit and tick it.
And to set the default for guests and new users, ACP > Configuration > Show Thread Options > Display posts using the classic layout.
Just so you know, 'that box' is called 'postbit' (don't worry, nobody was born omniscient).