[AllanJ]

Start with the research.

... If it is legal for one pump and well to serve two homes,
... If the pump has enough capacity (gallons per minute)
... if the well has enough capacity (GPM) for a continuous draw over so many minutes.

The piping from the pump to the second house can be designed as if were the only house.

Install a 30 gallon pressure tank at the second house, before any further branches to different bathrooms, water heater, outdoor spigot, etc. (The first house should also have had a 30 gallon or larger pressure tank but you can leave that unchanged for now.)

Refinement: The second house may be fitted with a (manual) switch to connect its power to the well when someone in that house is using water. A relay (contactor) is the easiest way of retrofitting the wiring so power from the two homes is not commingled.

 

[AllanJ]

You won't run into problems until usage from both houses at the same time exceeds the capacity of the well or the well pump.

A storage tank, if needed, is usually unpressurized and is usually put before the pressure tank(s) and the booster pump (can be a shallow well style pump) goes in between. The existing well pump is then controlled by a float switch and optionally also with a timer to allow X minutes of running and Y minutes of delay to let the well recover (then repeat). Does not need to wait until night time.

The booster pump is controlled by the (existing) pressure switches and also by a float activated kill switch if the storage tank, preceding, empties out.