New member account cannot reset password

The following procedure can be used to reset the root user's password.
As for the email, it should be delivered to the email you set up when you created your AWS account.
If you have not received an email for more than half a day, we recommend that you contact AWS Support using "Account and billing".
https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_accounts_access.html#orgs_manage_accounts_access-as-root

1. Log in to the AWS Management Console with either as IAM user of the management account or with a delegated administrator’s credentials.
2. Go to the AWS IAM console.
3. Select “Root Access Management”
4. Choose the member account where root user credentials need to be recovered.
5. Click the “Take privileged action” button for the selected account.
6. Select the “Allow password recovery” option. If “Allow password recovery" is not available, then click “Delete root user credentials”
7. Repeat steps 3 to 6.
8. Follow the on-screen instructions to confirm the action and initiate the password recovery process for the member account’s root user.