Pausing or resuming a campaign, ad set, or ad
You have the ability to pause or resume individual ad sets and ads within a campaign. This can be done by navigating to the ad set or ad tab within the dashboard and switching the delivery toggle for whichever ad set or ad you would like to pause or resume.
You can pause a campaign by pausing every ad set within the campaign.
Note: If you pause delivery of your ad set or all of the ads within the ad set, you'll only be charged for the delivery you've accrued to that date.
More campaign management help: