My knee feels like there is no cushion. especially when i squat or jump. why? 18 yr old female.

Knee cartilege: If you had no knee cartilege (what you call "cushion" you couldn't jump, let alone squat.

Depends: There is no way of telling over internet. However if pain is near knee cap (front of knee) this is common in females. Squats and jumps put a high load on your patellar tendon. As you strengthen your quads with those exercises, however, your knee pain may get better.