To create a new journey from a Primary Campaign you previously made and saved, locate the campaign and create a new journey for it. (It must have an approved status.)
Create a New Journey from an Existing Primary Campaign
Select Campaigns > Manage.
Locate your campaign easily by clicking the Approved tab.
In the Status column for the campaign, click Approved.
In the pop-up, click Ready to Schedule.
Select Create Campaign Journey.
Build Campaign Journey
Proceed to step 4: build a campaign journey.