Assume the lander the colonist use is a Red Dragon (since nobody else is building a human mars lander AFAIK.) It will act as a temporary shelter but with only 10 m3 of volume this should be for a very short duration. No more than a few days. Although it can hold up to seven astronauts, no less than two and no more than four will go on this first landing. The rest of the volume will have essential supplies. Which includes an electric tractor with a 40+ km range and an unfolding trailer that can comfortably hold the crew and supplies. They will need this vehicle to reach a pre-prepared site. Hopefully they will have landed within only a few kilometers from a supply Dragon already on the surface.
They're priority is to set up the first permanent habitat which should be large enough for themselves and others waiting in orbit to land. It's not meant to be pretty. It's meant for survival. Pretty comes later.
They will be leaving the dragon they landed in to get to the nearest supply Dragon which will be their second temporary shelter. This one will be packed full, so they will have to unpack it so they can use it for a few days while building the new shelter. The site prep might only be a trench or it could be a buried inflated tube with an airlock at each end. Either way, it will require the crew to finish up.
In their supplies will be four lightweight aluminum airlock doors (later they will make more from ISRU iron) which will have a ring around the frame on both sides for attaching a stretch airtight fabric. These doors will be rounded rectangles, not circles. It will also have fixtures for hoses and electric ports. At four corners poles can be attached to separate two of these doors forming the airlock. In supplies they will have aerosol spray sealant for where the fabric meets the door frame. They will put together two airlocks and test that they can hold full atmospheric pressure and should be positioned at both ends of the trench waiting for the inflatable tube that will extend between them. This tube will be attached to both airlocks, sealed and inflated. Then the entire shelter will be covered with martian dirt.
They might have figured out to move supplies into the shelter before they attached it to the airlocks and inflated it. If not, they will have to move supplies in through one or both airlocks. This will include a heating and cooling unit and batteries that might come from rovers. They have a cord that runs from the Dragon to one of the airlocks electric ports. Later, after the shelter is up, they can deploy solar panels for additional power. Setting up this first permanent shelter should not take more than a few days. They should then work on finishing up secondary shelters near other supply Dragons.
I propose the volume of this first permanent shelter be 10x10x50 meters or 5000 m3. This will be a nice change from the 10 m3 of the Dragon. The reason for a 50m length is it fits into the size of a plot in another proposal of mine. How they decorate the interiors of their shelters is up to them. Once survival is taken care of they can make new habitats using local materials using any design they come up with. It's called liberty.