There are many I’m sure. I had bad knees, and did and do a range of exercises that have worked wonders. The main one is the Bulgarian split squat. Stand in front of your bed or a chair with your back to it, one foot in front and about two feet from the bed/chair, one foot behind and resting on the support. Now move your body downwards, keeping your back straight, until your front knee is a right angle. Then rise up. Use your front leg, not the back, to lift. Repeat ten times on each leg. Videos on YouTube will make this clearer.
It is very unpleasant, I loathe this exercise, but it works and does strengthen muscles around the knees. You can also do simple squats without weights. Maybe place a gym ball behind you against a wall as a partial support. Squats with dumbbells too. Gyms have machines that allow you to push against weights, that might help.
I can skate on one leg, and drop down, I can’t do the teapot (pistol squat).