Replacing 2 wire switch with 4 wire switch, box has 3 wires. Help?

I’m trying to replace a light switch that has 2(Red & Black) wires directly connected to the switch itself with a 3rd(White) wire that’s capped off in the box with a new smart switch that has 4(Red- Load out, Black- Line, White- Neutral, & Green- Ground)wires. Is the white in the box neutral? The old light switch has a ground screw and the white wires aren’t connected to it so I think they’re neutral. And if that’s the case what do I do with the ground wire from the new switch? Do I connect it to the screen in the back on the box? Help. Thanks!!!

Is this screw for grounding the green wire from new switch?