Your Chevrolet is then automatic.
Maybe you have a rod which will show you at the oil level you have.
To measure the oil level you must:
1- Turn on the vehicle and leave it with handbrake.
2- Pass all the gears of the lever so that the valve body of the box is filled with oil.
3- Remove the rod and see, as the motor oil, the minimum and maximum marks is seen.
If you miss it, you must fill it to the marks set on the rod with ATF JWS3314 type oil for automatic transmissions.
When you walk with little oil in the box this tends to heat and lose certain properties, in addition to the greatest cases some internal elements of the box can be worn, which leads to very high repair costs.
I hope the advice serves you.