O2 sensor

my check engine light came on during a long distance drive. stopped at auto zone and they said it was probably the o2 sensor. i have to make the 9 hour drive again, will the bad o2 sensor hurt my car? should i get it fixed before making the drive again?

If Auto Zone didn’t scan the engine computer, the “probably an oxygen sensor” is worthless. If Auto Zone DID scan the engine computer, you should have the code, such as P0401, etc., to show us. We need THOSE codes.
If the check engine light comes on steady, that means that some part of the emissions system has circuit values which are improper to the expected values.
When a sensor and its circuitry values are outside the expected, the engine computer substitutes values from a look-up table which are usually “close enough” for you to continue to operate the vehicle for a while.