Hi Olga,
By definition, the fold is at 100vh, meaning 100 viewport height. If you set the height of your hero section to 100vh, it will exactly fill the visible height. You’ll need to adjust your font sizes and padding to fit your title properly.
I’d also probably set a minimum height of something like 500px so that if the vertical space is too narrow, it doesn’t break the hero entirely ( in that exceptional case, it would simply extend past the fold ).