Excuse me, what is the correct and standard standing posture for young men? Sitting position? Sleeping position?

Stand: Look straight, hold your chest up, hang your arms naturally, and stand with your feet slightly apart, forming a slight figure eight.

Sit: look straight, chest up, arms resting on the handrails or resting on the legs, legs slightly apart, feet flat and apart.

Sleeping: There is no standard, as long as it is not curled up, lying down, or stretched out. It is generally natural to sleep on your back or side.