You don't need to go far outside Paris to get a complete change of scenery: you can find wonders just 1h30 drive away. What are you looking for? Castles? Palaces? Forests? Medieval towns? Quaint villages? They can all be found!
And, you know what could be great if you visit Paris for at least five days? It would be to plan two or three nights where you stay outside Paris on a short customized multi-day tour to Normandy or the Loire Valley! Just tell me when your plane lands and when you fly back, together with your motivations, and I'll come up with a potential itinerary depending on opening days and what works best to make the most of your time depending on the pace you prefer. I'll also give you recommendations where you (and I!) can spend the night while on tour but you can then do your own research to choose another accomodation because, at all times and at all stages, you choose every single option!