On most vehicles the OBDII port is located under the steering wheel. Sometimes it might be covered by a plastic cap.
Here are the most common OBD port locations:

Alternatively, if you cannot find the OBD Port make a quick Google search for your vehicle make, model, year and the words “OBD port location“. That should give you the exact location.
You might also want to check YouTube – there are tons of videos available for almost any vehicle make and model.