Samantha Matthews has a really great program on Knee Therapeutics that you might want to check out first. I've linked the first video. I've linked another video that is mainly seated to help you ease into yoga. The last video does not put a ton of stress on your knees, but be aware it is a little tougher. If you search for knee related videos, you will be able to check out different collections that other users made and pick and choose your favorite ones from there. You can also create your own collection when you find videos that you enjoy. Here's a link on how to do that: https://support.grokker.com/hc/en-us/articles/360000164012-How-do-I-create-a-Collection-