To import images from your camera, there are two ways to go about it.
Method 1. Download images from a memory card.
Connect a card reader to your computer and insert your memory card into it. When you do this, an Import Images dialog should appear. If not, you can manually pull one up via File -> Import Images. To set this to automatically appear, open Preferences -> General and enable the setting as shown below.
NOTE: Capture One is not designed to recognize cards that are mounted within the camera; rather, it is optimized for a tethered workflow with cameras and communicates over PTP (camera control) rather than as a Storage Device. It's necessary to download the images off the card via a card reader or internal card reader.
You can then proceed with the rest of the import process, as outlined here:
Method 2. Another way to import images is to do that manually, using the Finder icon which is located at the bottom of the screen as shown in the image below.
By clicking on the Show selected in Finder icon, a window will display all the Session folders. Open the Captures subfolder. Open the mounted CF card reader drive, select and move image files into the Captures folder of the Session. Once images are in the Captures folder, thumbnails and previews will be created.
Images dragged/copied into the Captures folder manually will not be renamed.
NOTE: Automatic import can be turned On or Off by navigating to Preferences -> Capture Naming Preferences and marking the Bring up import option when a Compact Flash card is inserted.