There are two ways to add contacts to your CallFire campaigns. You can either select contacts when you are creating a campaign, or you can reuse lists that you created elsewhere in the system. Here's a brief overview of each method.
One way to add and select contacts is to do so when you create a text or broadcast campaign. You access this via the Contacts tab, as shown below. There, you are given five options for creating lists of contacts: Upload; Choose Lists; Add Contact; Filter, and Copy & Paste. All of these are detailed in the Contact Selection section of this help section.