No -- if you resume a 'Paused' Campaign, existing prospects will remain at the exact point in the campaign that they were in when it was paused. When the Campaign is resumed, they will proceed through the flow(s) as designed; they will not restart flows, repeat Campaign Actions, or in any way deviate from the designed behavior of the campaign.
Note - Any prospects that were sent to the campaign from new Audience lists, associated forms, or other Campaigns while the Campaign was paused will begin at the Start Action when the Campaign is resumed.
To learn more about the Campaign Start Action, click here.
To learn how to build a Campaign, click here.
To learn more about Campaign Flows, click here.
To learn more about Campaign Actions, click here.