Hi I'm 19yrs old and a female I'm 65kg and 5'3 in height.
How much weight should I loose to get a perfect and healhty body.

We can't tell from that information. There are athletes in the Olympics right now who have your stats, and look amazing. And there are people with the same stats who wobble when they walk.

I would worry less about the scales and concentrate on getting a slimmer waist.