Is it fine to wear a glasses all the day if i am short sight person. is better to wear contact lenses?

Doesn't matter: You can wear either - doesn't matter. It's really a matter of personal choice and appearance. Contacts require more discipline in hygiene ; routine however. I started wearing glasses - initially when necessary but then all the time - for near-sightedness around your age. It will take time for your eyes to adjust ; u may have headaches initially but that will pass. Contacts also require adjustment.

Either: Both are fine. Theoretically less accommodative strain when you wear nothing for near focus activities provided you don't have significant astigmatism. Glasses are second best and contacts third best. But really if you are comfortable, all the above are fine.