In this YouTube video a new composition is created then importaded footage is adjected to comply with the created new compsition (50 scale is given). Time 00.27 to 01.36.
In my view staight away you can use New Composition From Footage to do this.
Here is there any reason using New Composition instead of New Composition From Footage.????
There is no reason to use "new comp from footage" unless you find it more useful. The person in the video is using just "new composition"
Issue is if footage is available is it necessary to create New composition? provided that if we are going use the properties imbeded in the footage.
Not 100% sure what you mean, but yes it is necessary to create a new composition using the properties you have. The properties that the footage has will be automatically applied you if you create a new composition from footage.
Here is there any specific reason for creating New Composition instead video footage is availabe to create a New Composition From Footage?
No, there is no specific reason.
It is cofusing because 4k video footage is used as a exercise document but full HD composition is created from New Composition button. That mean for higher resolution vido footage a lower resolution full HD composition is used. I do not know whether presenter aware of availabilty of New Composition From Footage button.