Have large dark floater & glaucoma in right eye & today developed large floater in left eye. Do floaters have anything to do with glaucoma?

No. The two are independent and represent separate eye diseases. Floaters could be a warning sign that a retinal tear or even small detachment has formed. They can also arise when there is bleeding in the eye. Although unlikely, blood that has not fully been reabsorbed can cause something called ghost cell glaucoma. An examination of the eyes is essential.
They usually do not. Usually floaters are associated with retinal problems. It is important to have a thorough dilated exam with onset of new floaters.
Floaters. Floaters are common and usually due to a change in the protein composition of the vitreous (inside gel of the eye). Rarely are they due to inflammation which can be connected with glaucoma (otherwise they are un-related). Check with your eyemd that they are "just" floaters and not inflammation in the eye.