Do leg stretches every day. Most knee pain is associated with certain muscles overpowering others in rest state. Stretch them out to reset that balance. It's worked wonders for me, started seeing results in ~2weeks.
My knee pain is associated with arthritis, unfortunately. I wish stretching helped. I'm even a couple years younger than OP, but when I walk up stairs it sounds like I'm crinkling two big balls of cellophane.
I usually do quad stretches, forward bend, downward dog, childs pose, pretzel, and figure 4. I think the figure 4 has had the largest impact loosening up the glute to knee connection.