When i walk, my knee pops multiple times. there is no pain but it gets sore sometimes.. what should i do?

Depends: Would need to know what is popping. Often times it is the patella, or knee cap. Other times, the knee can be shifting. See a specialist, get a proper diagnosis, and it may be as easy as having some physical therapy session.

See a Specialist: The soreness is letting you know something is amiss. You should see a specialist to have it evaluated.