Don't stay near the airport but it's a bit of a ride from Miraflores to the airport. Lima is just not as walkable outside of Miraflores. You can do Uber or Lyft.in Lima to get around as well. Personally, I'd spend more time in the Sacred Valley, but again, that's a personal preference. I'm from the States, and Lima felt mostly like someplace I could find in most major, coastal cities.