A Contact can be manually added directly to your system.

- if you want to import multiple - please refer to that article

To Create a Contact manually

From your Contacts tab on the left, choose Add New Contact.

Enter the contact details, and click Save

The contact is not yet associated to any Campaigns, or the Funnel.

Click the button to assign the Contact to a campaign. 

The contact is now available to be called as a part of that Campaign.

Note: You are required to enter a valid Phone number before adding a contact to a campaign

There is also an option to Create Lead to add to the Sales Funnel directly