Nobody can tell you anything without proper info about your comp, your footage, your version of AE and your system.
Stabilize motion requires you to have the footage you want to stabilize in a composition, the layer selected, then you pick the footage you wish to stabilize by selecting the Motion Source in the Stabilize Motion panel. This will open a layer panel where you set up the trackers and track the motion. This is easiest if you have the Motion Tracking workspace selected.
I would strongly suggest that you type Stabilize Motion in the Search Help field at the top right corner of AE and then follow the links to some tutorials. The workflow is fairly easy to understand but it's not as easy as just clicking and then the magic happens. You need to learn how the tracker works to use it effectively.