Stretch your leg muscles properly after cycling and indeed daily regardless of cycling
a sports physio would be the right place to go if it doesn't get better. Are you resting between rides? Or are you not riding and the aches and pains are not caused by cycling? Your post isn't entirely clear
How old are you? Stiff and aching can be sign of arthritis? Where in the leg and knee is the pain? Does it also occur at night?
What are the other health issues to which you refer?
Clicking without pain doesn't always need medical attention, joints do click, especially as we get older
. You should hear my joints, ok some of them are knackered, others aren't buy they still click!