The first live-action appearance of Superman on screen was with Kirk Alyn playing the lead role. This 15 chapter serial finally brought the Son of Krypton to movie audiences, but was hampered by that era's lack of the necessary technical effects to make the Man of Steel really fly, although Captain Marvel's flying proved better on screen. Flying was achieved with animation, which did not work well. However, the serial was a commercial success and gave us Noel Niell's Lois Lane, which she reprised in The Adventures of Superman with George Reeves. Interestingly, as noted in Wikipedia, animating him from live-action takeoff to animated flying was easier to do than animated flying to live-action landing. So they had animated Superman land behind something then he would pop out as live-action Superman.
Kirk Alyn was offered the starring role in The Adventures of Superman television series but refused it, not believing in the Superman Curse, in which anyone portraying the character would be typecast and not hired for any other role. Alyn eventually said "playing Superman ruined my acting career, and I was bitter for many years about the whole thing. I couldn't get another job in Hollywood." George Reeves, who did take on the role in Adventures died two years after that series ended, whether by his own hand or someone else's is still a mystery.