Thanks for taking the time and posting the video.
OK, don't worry about which foot to land on. Worry about learning to swing a groundie stroke correctly, build up some rackethead speed, get in condition to move quicker and do it, which now takes 2 years, THEN learn to serve harder and post a vid.
Whichever foot you land on after you serve is your LEAST important consideration. Which by the way, the answer is EITHER foot you want.