I'm 22. As long as I can remember my left knee & left ankle always pop when I walk or workout & they also ache a lot. Any ideas?

Let me try to help. So long as you aren't in pain, popping is normal, and it has the medical name crepitus. It's almost always harmless, but it surely can be a conversation starter- my knee joints have always been noisy.But if start bother you please check it out.Good luck.
Observe. Popping of the knee usually is not significant e.g. Knee cap with knee bending. If it's painful or associated with catching, that's significant and may indicate a meniscus tear. For the ankle tendons sliding by the bony prominences can cause popping but not be significant. Obsvere.