the second image is useless, as its too closeup. we cant see what it is…
anyway, if its one face overlapping another, then move one of the faces 0.0001cm away
or just delete one of the faces…
i would actually guess that you are inside the mesh now, since this does not look like anything that could happen form what you got on the first image, if that is the case, then dont bother. its inside the mesh and noone will ever see it