which foot should come thru first ? either one is okay
Brian Gottfried brought the hind leg into the court first, called cross over step,,Roscoe Tanner brought the front foot on to the court first.
As to serving motions and foot work
Windmill -type serving motion(full backswing) front foot land first on the court.
The Half Swing serving motion(trophy pose) hind foot lands first(crossover step)
These are learned motions, your coach is pointing out one of them..