A brand new O2 Gas Sensor does not need to be calibrated, but the sensor will drift over time and will need to be calibrated.

To calibrate the sensor, follow the normal 2-point calibration procedure.

-For the first point, push and hold the calibrate button on the sensor using a paper clip or LabQuest stylus.
-Enter a value of 0 for this reading.
-Release the button and take a second reading in air.
-Enter a value of 20.9% oxygen or a corrected value from the table in the sensor booklet.

Since the timing of when you press and release the calibrate button on the sensor is important, the video below should be every helpful:

Using your LabQuest 2 stylus or a paper clip, you can easily calibrate your O₂ Gas Sensor. #VernierTechTips

A video posted by Vernier Software & Technology (@verniersoftware) on Nov 3, 2016 at 12:00pm PDT

See also:
O₂ Gas Sensor Troubleshooting and FAQs
Can my O2 Gas Sensor (O2-BTA) be repaired?