[dad911]

They should have taped over the joints.

I would use mesh-stick on tape and put it over those exposed joints.

Then a thin layer of spackle to cover the tape, let dry.

To texture, practice on some scrap. I could get pretty close to that by putting on a thin layer of spackle, then "pull it" by putting a flat blade on the wet spackle, and pull perpendicular away to raise the spackle.

I suspect you could also get close, without tools, by pushing saran wrap into the spackle, and pulling it away.

Or try a dabbing the spackle on with a damp sea sponge.