You need to connect a GPS unit. Take a look at the store for the carloop pro. You can see clearly that there is a separate GPS receiver that gets plugged into the GPS connector on the carloop.
If you do have a GPS, the GPS needs to get clear signals from the satellites. Make sure the GPS is not blocked from the sky by things such as the metal roof of your car or being inside a house. Trees and clouds can make it difficult to get a signal sometimes.
check for any GPS setup code in the setup() section
try running it outdoors with clear view of the sky
give it plenty of time to acquire that first signal
(once you get the first signal, subsequent times will be much faster. Also, keeping power to the GPS keeps its satellite library alive, which makes reconnection much faster.)
If that does not work, contact carloop support and see if they can help out.