Once your group has been approved for access, click the "Campaign Page" button in the "Create A Sponsored Action" sidebar on the right to create a new campaign page.
On the create page, give your campaign a title and a description, and add an optional image if you choose. Then, click the "Add or Edit Actions" button in the right sidebar to add featured actions to your campaign. Choose any action sponsored by your group from the list on the right and click the green plus icon to add it to your campaign's featured actions. Click the red minus icon on the right to remove an action, and click an drag on the vertical dots to reorder actions. When you're done, click "Save and Close" to save your choices and preview your featured actions in the one-to-one interface.
Four actions can be displayed at a time on your campaign page -- any additional actions will be available using paged navigation on the bottom of the sidebar.