Q.Orchids
My orchid flowers, which have been in bloom for weeks, have started to drop off. Should I cut back the stem or leave it? Do I continue to water?

You may want to wait till fall to do major pruning of that kind. Decrease watering for the remainder of the summer as long as there are no additional buds getting ready to bloom. Cut back on watering altogether once the plant is dormant.
This article may help you:
https://www.gardeningknowhow.com/ornamental/flowers/orchids/how-to-prune-an-orchid.htm
https://www.gardeningknowhow.com/ornamental/flowers/orchids/indoor-orchid-care.htm