A home inventory can begin with one cupboard or shelf. Write down the items you keep there and add a brief description when several look alike. The first version can be a plain list in a notebook or a basic digital document.
For equipment, record the model name and where you keep its instructions. For shared supplies, note their usual storage place so other household members can find them. Include only details that will be useful when you need to locate or identify an item.
Update the list when something is moved, given away, or replaced. Working through one small area at a time keeps the project manageable. The purpose is to create a useful reference, so a clear and current list matters more than a complicated format.