I'm worried I've damaged my kness from squats. What are the signs?

Hard to say. Proper squat form is so important to keep your knees healthy. There are a myriad of ways you can damage your knees with improper squat form. But, knee pain could be from many things. Old injuries that never healed, improper running form, etc. Best to have a good knee exam to be sure and then follow up with someone who can critique your squat form.