Love the Gua Sha
Just as you should be careful when you start training your muscles in the gym, should you be careful when starting to the train the muscles in your face with face massage. Results take time. Start slowly. Do not overdo it. Be reasonable with your expectations.
Give your muscles time to rest between exercises. Always clean your skin before any exercise. Use a gentle soap, and luke warm water. Clean also your hands and make sure your finger nails are clean too, to ensure you're not poluting your skin.
Also, if you have a special skin condition, then you should first ask your doctor or dermatologist for advice before attempting any of these exercises.
Remember, your are doing this to become a better version of yourself, so be kind to yourself, love yourself, don't give up and be reasonable about results.