Does anyone know the exact measurements of the three walls, like the diameter of all the walls combined and the distance between each wall?

I don't believe it is ever specified what the diameter of the walls are. But by their shape from what i can remember, they are not perfectly circular so a diameter wouldn't do much good for measurements. Now they might have specified the distance between the walls but i don't believe they did или i didn't see it.

In ep 1 it сказал(-а) that the distance between each is roughly the same.
Maria to Rose - 100 km
Rose to Sina - 130 km
Sina to center - 250 km
The diameter is 960 km
So the Стена is a bit bigger then France.