
I want to know how these clothing sets are being photographed? is it on hangers or on the ground? How can I blow out the background completely like this?

I want to know how these clothing sets are being photographed? is it on hangers or on the ground? How can I blow out the background completely like this?
It looks like they are being photographed using the "Ghost Mannequin" technique or a slight variant of it.
Usually clothes are placed on a mannequin, photographed and then photographed again inside-out. The two images are then put together in post-processing. In this case they may have varied it slightly by placing the clothes out flat, but broadly the technique looks the same.
For more see here: How to do the ghost mannequin effect?
It looks like it's photographed on a ground (noticed that everything is flat), most likely from a height (ladder/stairs/window on a 1st floor ;) ) on a large sheet of white paper/cloth (either laying horizontally or at a slight angle).
Considering how evenly lit the clothes are I guess photographer used 2 flashes standing on a sides with either umbrellas or (more likely) large reflectors / softboxes. There are several light setups that can be used for such effect.
In either case - it looks like a rather professional setup.