You can travel at whatever pace you set. Some like to make a string of one-night stays, I prefer at least 2 nights and sometimes spend 10 days in one spot. Using local transportation is easily learned even for retirees like me who have never lived in a city with public transit. Some countries it works better to book train travel ahead for a discount. Some countries, it doesn't matter. You'll want to do research to figure out which is which.
Paris? Five years ago I might have thought it was over-rated, then I took a Rick Steves tour that ended in Paris and got some lessons on how to manage there, then added on the Rick Steves Best of Paris for a week and have returned again and again. My previous view of Paris was based on how I saw it in the 70's. Paris...and I...have changed since then!
What is MWR tours?