Through the 1920s and well into the 1930s, WIlliam Boyd was a successful actor...but also one that wasn't super famous. He made a decent living but his stardom went into orbit once he became Hopalong Cassidy in a series of 66 B-westerns. "His First Command" is one of many, many pre-Hoppy films in which Boyd starred.
Terry Culver (Boyd) is a rich young playboy whose primary interest seems to be women. However, when he becomes smitten with a Cavalry unit's commander, he joins the army just to impress her...which seems pretty strange for a playboy. For much of the picture, he seems like a bit of a jerk...though ultimately he gets a chance to prove himself a hero.
In many ways, this film is very reminiscent of the films William Haines was making at the time. Such playboy roles were common for him, as well as him going from a blowhard to an all around great guy and getting the girl. Overall, a decent little film...not great though quite entertaining and worth your time.