So the N95 or N100 masks are actually considered particulate respirators. all healthcare staff should have been fit tested already upon initial hire at your facility. This was primarily for tuberculosis protection at that time.
Even though I think some respiratory protection is better than nothing, you need to be able to breathe. Some people can't wear the particulate respirators such as N95s because of respiratory disease or facial hair that prevents a good deal. Those folks are better off with a powered air purifying respirators which have a hood and a power pack. These are probably hard to come by.
Make sure your N95 is a good fit. Be sure to bend the nose-piece to make a good deal.
I believe COVID-19 is spread from respiratory droplets, but is also airborne. I am disappointed that the CDC backpedaled on requiring provision of respirators to employees caring for these patients. I think the lack of N95s caused CDC to recommend surgical masks as an acceptable alternative. a bad decision in my opinion.
If you don't have particulate respirators, a t shirt mask is better than nothing, a cotton fabric mask is better. A surgical mask is even better and a respirator is best of all. However, you also need a face shield, preferably a full face shield. Safety goggles at a minimum.