Perhaps a better place to start would be, what do you want your sensors to do? There are many different kinds of sensors for many different needs.
Some common tasks that robotics sensors can help you achieve:
-Reading the angle of an appendage (such as an "arm") being turned by a motor
-Reading the speed that a motor is turning
-Reading the distance that your robot has traveled
-Reading the angle or acceleration of your robot
-Sensing the presence of objects at a short (or long) range
And so on. Clearly there is lots of useful data that can be gathered from sensors. Work on narrowing down your goals: figure out which tasks you want to complete using sensors.
In the mean time, the document below will provide a basic intro into how sensors are incorporated into LabVIEW:
https://decibel.ni.com/content/docs/DOC-26312