Cant able to setup Control Tower on new Account

I understand you are in Management account and not able to enable control tower. If you are in account which is already part of AWS organization and error message should be "To set up your AWS Control Tower landing zone, you must log in to the management account of your organization. Your current account is not the management account. Change accounts and try again."

can you please try to" Disable AWS Control Tower from the AWS Organization services." I couldnt replicate the issue from my end but you can give a try with this option.

Hi there.

The error message indicates that Control Tower has already been enabled in a different account. You said this account is new but this doesn't mean it is the only one. You already have an organization and CT enabled. You don't need to enable it again, just keep using the one instance you already have.

I hope this helps.