The sewing process of the cloth simulation needs Self Collisions to work. Without it, the simulation basically can't make the vertices of the cloth interact with each other, they can only interact with other objects with collisions enabled.
Start by enabling Self Collisions here:

You should already have a functional simulation just with that. All that's left to do is playing with the parameters to get the look you want. I'm not an expert in that, so I'll leave it there.
On another note, a few advices to avoid issues down the line:
You model is over 2 meters high, it's quite tall for a human being. Just to give you an idea, this is a cube of 1.73m height and 43cm large/wide, which is an average human dimension:

Since you are doing physics simulations, measures matter. You are not too far out of scale, so it might not be that troublesome to keep it like this, but I advise you to scale that character down.
I'd advise applying the mirror modifier as well as the Rotation and Scale via ⎈ CtrlA > Scale to avoid further issues.
Also consider lightening your mesh. Fewer polygons are faster to do physics simulations on.