A user with system admin permissions should have the option to select Themes from the dropdown option as seen in my first screenshot:
This will allow you to then go to Advanced and enabled Custom Links Enabled, as shown below. From there you can decide which tabs you would like to be shown on your homepage, one option is Places which would show you the places in your Jive environment.
In regards to changing the order which the All Activity displays, unfortunately there is not an out of the box way to make that customization change.
Hope this helps.