Select a sprite you have added to your layout...
(Either from the layout directly or from Project or Object Panel)
On the "Properties" panel you have various properties you can edit such as the name its layer angle etc
One of these sections is called "Instance Variables"
Under this section you can add variables that are directly attached to the object... rather than creating local and global variables in the event sheet.
If the sprite is your player you might add a "health" value or something similar