Gravity would be best at the middle of the dark side of the moon

At the dark side of the moon, at the furthest parts from the moon, or at the middle of the dark side, that would be the best location for a base since the gravity of the earth affects you better there in addition to the gravity of the moon.

You could have a slightly heavier gravity pull in that one direction.

At the light side, at the middle, you would you weigh the least.

The pull of the earths gravity is mostly closest there and it’s pulling you from above you making you lighter.

Where on the dark side, the pull is slightly weaker since your further away from the earth but it still has some pull making you slightly heavier since it’s pulling you down from below your feet.

Just like how the moon affects the tides on earth, the weight of the earth pulls down on the moon. The earth is not rotating around the moon meaning the gravity is constantly fixed.