So, is drywall dust toxic? Yes, it is ... At the very minimum get some lightweight disposable masks like these 3M Particulate Respirators. Be sure to buy N95, which is made to US safety standards ...

a package of 150-grit drywall sanding paper that's precut to fit your sander, and a sanding sponge for corners and detail sanding. You'll also need a double-strap dust mask rated for nuisance dust ...