If you can see an ABS sensor plug at your front wheel going into the hub, you may not see a rotor or teeth visible as the ABS type bearing has a plastic seal which on the end facing inwards towards the ABS sensor it has a series of magnets that act like the rotor and are read by the sensor.
A few points,
One, do not touch it with anything magnetic as it will destroy it so you will end up buying another new one, even cleaning the ABS sensor hole with a screwdriver before fitting a new sensor.
Two, make sure you fit it the right way around as magnet only one end.
Three, make sure the circlip that holds the bearing in the hub does not obscure the ABS sensor hole as it will damage the sensor.
Four, it is usually best to carefully press the new bearing fully into place, so if you ask a garage etc. to do it make sure they follow those guidelines.
Visually there is no way to see if a ABS bearing is damaged, unless you have a suitable tester, I use a special credit card like thing with metal or graphite inside it made by SKF bearing company, if you hold it against the correct end of the bearing it will show the magnets in the rotor type position or blank/damaged bits if it is faulty.
I have posted a picture if this in the past, though it make take a while to find it.
