The Organization Settings page is only accessible to Administrator users. It can be found by clicking on on your username in the top right corner and then selecting “Organisation Settings”
This will bring you to the Organisation Settings page.
To change your organization name, edit the current name in the text field and click save.
The organization timezone is the default timezone for all users in your organization unless they select a specific user timezone. To change it, click on the timezone tab and select the appropriate timezone and then click save.
See here for details on changing your subscription or billing details.