Leaking Drain valve on Water heater

I realize this is a pretty basic deal for you folks, but it's a bit bothersome for me. I have a leak at the drain valve on my Rheemglas Fury hot water heater. Looks from dampness around the heater that it's been going on for some time. Any chance this can be something I can do myself to repair this?
Thanks for any input.

Is it the drain or T&P relief valve. Both are easy changeouts, unscrew the old screw in the new.