When you launch a goal in Perpetua, you will have 3-5 campaigns launched in Seller Central or the Advertising Console. You can read more about the campaigns that are launched based on the type of targeting you choose here.
If you would like to pause any of these campaigns there are 2 ways that you can do this:
After clicking into a goal, scroll down and select the "Campaign" tab. From there, click on the arrow to the right of the Optimized icon, and select "Pause."
To then restart a paused campaign, click on the arrow to the right of the Paused icon, and select "Optimize."
After clicking into a goal, click the Advanced Settings button on the bottom of the Optimized Panel.
Select the "Campaigns" tab. From here, you will now be able to toggle any of the campaigns on or off.
Once you've done this, press "Done" and then hit "Update" to save your changes.