You start 1 km above the surface with the engine cold. Lunar gravity is
1.62 m/s² and the descent engine pushes about twice your weight, so plan the
burn early.
To land: both feet on the green pad, under 2.5 m/s down, under
1.5 m/s sideways, within 12° of level. Hit harder than 10 m/s
and the legs fold.
Less fuel is a lighter, livelier lander. More fuel is a bigger margin and a heavier ship.