Why the girl has to move out of house of parents on marriage. How this custom came into society?

well, as the tradition of man being able to support his own family hence, the girl has to move out as a proof of that man is able to do such a thing however, modern days aren't showing good signs of that recently

Probably depends on which society you are looking at, maybe not all societies insist on such a move. But the move does indeed prove that the husband can look after the wife if he can set up an independent home. Back in primitive times the female would be looking for a virile male who could father healthy children; probably still the case deep down.

That's the point of the father giving his daughter away to her husband when the two become 1. If your not ready to move in with your husband and become a new family y probably not ready to get married. This is an old testament tradition.

She can stay in as well if perants have 2 homes!

from the Bible to start their own family.

u HAVE TO ASK YOUR FOREFATHER