When people first started working from home their home office was usually a spot on the end of the dining room table. Or if they had a laptop, maybe it was on the most comfy seat in the living room. However, the home office has now evolved to become a dedicated space more suited to the user’s needs. Where you put your home office will depend a lot on your lifestyle and stage of life as well as on what you use the office for.
If you have children at home that need to be supervised, your home office will need to be somewhere in the home from whence you can see them and tend to their needs, rather than a room you can go into and shut the door. A corner of the family room would be a good place. Here you can set up your desk and have some kind of storage. You may also want a box of toys to distract the children with so you can get on with what you are doing.
If your children are at the stage where they can amuse themselves or are going to school, you can still have your home office in the corner of the living room as there will be no distractions through the day. However, if you have a spare room you might consider converting it to a real office space, especially if you need to use it a lot. You can have a space that is all your own and be sure that there will be no disturbances.