Pausing an ad or adset in AdEspresso is very simple. You first need to navigate to your campaign's dashboard, and then click the All Ads tab.
From here, you can select the pause button to pause any of the adsets:
or click the show ads button to pause the ads within the adsets.
Pausing Ads and AdSets and How Budget Reacts
Keep in mind budget management with AdEspresso works similar to Facebook.
When you pause an entire adset, that budget is removed from the campaign. You will need to edit the campaigns budget to keep it running with the amount you originally set after you start pausing adsets.
If you pause ads within an adset, and the budget is redistributed automatically to the remaining active ads within the campaign.
You can view this article for more information on how to manage the campaign's budget: