It’s not possible for us to know the password or which extension was set as the system owner, as this is a new system. I recommend stopping the instance from the 3CX portal, waiting about 5 minutes, and then redeploying a new instance. At the end of the setup, a page will appear showing the account details—please make sure to note these down, as they will no longer be available once the page is closed.
I can also see that you've contacted our CSR team, who will ask you some questions to determine if they can assist you with the current system.