@crystalena Airway clearance is the process of using any of a combination of deep breathing, huff coughing, postural drainage, mechanical devices and exercise to assist in expelling mucus from the airways.
Here is a long but excellent video describing how to do it.

After trying several techniques, most of us settle on one or two that work best for us.

If you are on oxygen, please talk to your doctor about whether to add saline nebs. You could also ask for a referral to pulmonary rehab to set up a good program for you.