please tell me how to find enemies? ...i always found enemies when they hit me
You find enemies when they appear in front of you.
It isn't like COD or any other shooter that lights up and shows a dot when somebody fires their gun.
However, there will be a "section" of your map that glows orange-red (as far as pubg mobile goes) for about 1-2 seconds.
This can help guide you in the general direction of an enemy firing their weapon, but will not pinpoint exact location.
I still find the sectional alert very useful, personally.