We don’t use sitting for beginners (this is not zen btw) they can lie down. The worst thing that can happen is they fall asleep (which happens on a rare occasion, most stay present through certain cues we use)

Sitting in half lotus or milder variations is hard for the chair accustomed person! Not to mention that lotus/half lotus can be tough, sometimes wrecking even, on the knees,hips or lowerback.