For Paused Campaign:
If your campaign status is "Paused" then you can start your campaign at https://cpidroid.com/campaign/install/manage.php by hitting green "Start" button given under "Actions" column.
For Campaign under Review:
If your campaign status is "Review" then you can start your campaign after it's approved. Once a campaign is approved, it's status is automatically changed to "Paused" by default.
When you create a new campaign, It will either undergo review for approval process OR initially be paused so that you can adjust some settings by editing it before starting it.
When a campaign is created successfully a message is shown which indicates the status of the campaign along with a quick "Start" button.
You can edit & control (pause, start, terminate ...etc) your campaign from your dashboard as well at https://cpidroid.com/campaign/install/manage.php