Hip/groin pain clicking noise. It feels like my muscle/tendon gets stuck when walking. Also causing knee pain. Painful to walk. What could it be?

Have it evaluated. Locking and clicking are signs of soft tissue or meniscus damage. This needs to be evaluated and treated by a specialist to possibly prevent future complications.
A pulled muscle/ten- Don, labral tear of the acetabulum comes to mind. See an orthopod to be properly diagnosed/treated. Might need an arthroscopic exam for dx/treatment. If the mri/xrays are negative or not too helpful. Hip lesions do cause pain in the knee area. Good luck.