Sensor Libraries

are used to extend the power of the programming languages.  When using the Arduino Tools, Manage Libraries ...  menu, a list of hundreds of libraries will appear.  Search for the appropriate sensor and try some of the examples.

Searching in Library Manager will reduce the number of choices.  For example, looking for HC-SR04 ( an ultrasonic sensor ) will list libraries that connect to that sensor
If the library has been installed correctly, the File, Examples menu in the IDE, will list some of the sketches that will work with that library.