I'm wondering what would be the best way to get inside a Moonbase!

In weightlessness, it's not difficult to imagine: docking hatches! No loss of air, very little volume needed (because people can fly head first from one module to the other) and in OG, modules can be perfectly aligned with those hatches....and stable.

On the Moon or any other world, people move in 2 Dimensions. And the ground is never completely flat. And we walk like on Earth. Docking hatches might be a problem. Then a door? Like the LM? Ok, but how does a moonbase grow then?
How do modules dock to each other? Yes, of course, telescopic legs...But that's not going to be obvious! A module would have a mass and the hatch would need to be tight for years!
Something different from cylindrical modules, perhaps (but there's a beginning for everything).