So what exactly a property is would also naturally be up for debate, but an example property would be say having a mass of 13kg. Or being pink. Most adjectives presumably are corresponding to properties, some would word my formulation as to exist is to be the subject of a predicate.

There are also relational properties, like being ten meters away from the Eiffel tower.

Some would call existence a second order property.

The Stanford encyclopedia of philosophy gives s good overview of the issues around existence. https://plato.stanford.edu/entries/existence/