In my country, in every house I've ever been to: no shoes on in the house. No shoes on in the room in the student dorm, no shoes on in any living quarters, period. Slippers are for walking in the house, you have a few pairs for different parts of the year: thick, warm slippers for the winter, sandals or flip-flops or something airy for the summer. You may walk barefoot in the house, or with slippers on bare feet, but only in the hottest time of summer. Otherwise always wear socks, whichever length and thickness is appropriate.
The main paradigm here is that your floor (with all the carpets) is clean, and while you can't and won't eat food that fell on it (unless it's really nice food and you vacuumed like 5 minutes ago), you can sit on it or put anything down on it knowing it's safe; and that the outside floor, the ground, the pavement, where dogs urinate and where sewer workers walk home from work, is FILTHY and disgusting. Consequently, the cleaner the part of your house, the more repulsive the thought of someone stepping in it in shoes. A child's room, for instance, or a bedroom.
The hall is where you keep your shoes, which you put on when leaving the house. You also keep your slippers there, and they are worn inside the house. No overlap. Unless it would be very inconvenient to take your shoes off for a second after you've put them on, like if you forgot to switch the light off; or you need to step out of your apartment for a moment to sign the mail receipt and it's a fuss to put on shoes. In that case, vacuum where you stepped (if you're a hygiene-obsessed neat freak like me, most people don't overreact quite that much) and thoroughly wipe off your slippers (definitely, everyone does that).
You may want to walk gingerly on the outer edges of your shoes when going into rooms beyond the hallway, as I often used to when I was little. Walking on your knees is another option I'd resort to back then.
Don't get me started on beds and couches. To even think to put shoes on these is just... No. Never. In my house, if you put your feet on the bed or the couch, you even take your slippers off. The couch is a very clean place, you can eat things that fall on the couch. You put your face on the bed and the couch, for goodness's sake!
Concerning guests: in your hall, you have several extra pairs of slippers. You give them to your guests if they're coming in for over 5 minutes and aren't standing in the hallway during that time. You do this especially if they are children. Adults may get a pass if they didn't ask for slippers and are only sitting in the living room and going to the bathroom. They may voluntarily go barefoot if you don't have slippers for them. You do not do this for strangers visiting you on some business.
I've learned, to my surprise, that this is a part of my country's culture and not present everywhere in the world. I'd always thought that American TV shows are just being lazy for not giving their actors slippers to wear while they're filming a scene in their room or lying on the couch. When in an American movie someone walks into their home and drags themselves to bed and goes to sleep with their shoes on, my family laughs at the uncultured peasant that person just showed themselves to be by my country's norms.