Yes, Centrigo provides two options to create trips from existing trips. For example, one of your friends shared a link to an existing Centrigo trip that they recently took and you like to use this itinerary to plan your trip. Then you have two options -
Save Trip
You can click on Save Trip option to create a replica of the trip that you can then modify and customize for your trip. Once the trip is saved then you can access this from your trips menu.
Subscribe Trip
You can subscribe to this trip and then access this trip at a future a date when you are starting your planning process. You can access a subscribed trip from your trips menu.