Welcome @Laurentfrom47 Happy you are here
You should create different packages 1 - Packages think of them as plans for your clients
Then create a new user account for every client they can use to log into the dashboard and create websites for themselves.
ACL is not important if you are not going to have resellers etc. If its just a shared cloud business model then leave this as user unless you are adding someone as part of your staff then you can add them as admin.