@Liza54 There are a few threads on this already- try the search box.
Personally, I offer guests a change of linens and towels after a week. I have a two week max stay. If the guest has, say, a 9 or 10 day booking, I'll offer that halfway though their stay, as it seems silly to change it out with only 2 nights left. Most of my guests have said it wasn't needed, as they go to the beach and shower daily, but I only host single travelers, so it's not like they're sharing a bed with anyone.
I also offer to clean after a week, but most also say not necessary- I've been lucky with guests so far- they keep their room and bathroom really clean and there is a broom and dustpan behind their bathroom door and a sponge for bathroom counter clean-up under the sink.