How can I properly board up my wooden garage wall for insulation and aesthetics, considering the boundary limitations and existing structure?

Hey everyone! So, I have a wooden garage that needs a little love. Two of the walls are covered with cladding, while the other two are just plain wooden planks. The structure is solid, but it definitely needs a fresh coat of paint and some tender loving care.

I’m planning on boarding up this wall that’s currently just plain wood, along with the others, and adding a layer of insulation. Unfortunately, I can’t put cladding on the outside of this wall because it’s right up against my property line.

Any advice on how I should tackle this project? On the other wall, I have the following setup: cladding on the outside, an air gap thanks to some battens, a breather membrane, a wooden wall, a frame with insulation, and more battens to hold everything in place. Eventually, I’ll be boarding up the entire garage.