Two Full Days in Paris. First time. Slower pace vibe.

I would suggest staying in the Latin Quarter - strolling along the Seine, walking distance to many large and small museums, Sainte-Chapelle, Jardin du Luxembourg, etc.

for slower paced enjoyment of outdoor experiences decide which aspect of Paris you want and stick with it for the two days -- Latin Quarter, as above? or Marais? or the Opera/Louvre area? or Montmartre? Commit to one neighborhood and stroll it. In August, do you want to be in the traffic or not?

regarding the question about train stations, you don't really have a choice of station. Each of the main stations serves trains to and from a particular region of the country. Provence for example goes into Gare de Lyon; Strasbourg and the Grand Est goes into Gare de l'Est; Lille, Belgium and England into Gare du Nord; Normandie into Gare St Lazare, etc.

Where will you be coming in from or going out to by train?

Read Rick's suggested itineraries (and those from Fodors and Frommers) and pick and choose. You have little time.

For August, I would be like looking for a hotel with ac in the Latin Quarter or Marais. Rick has some nice walks through these neighborhoods that you can follow.

Latin quarter is good for a first super short visit. Luxembourg Gardens is a lovely place for a stroll as are the streets nearby. The promenade plantee which is on an abandoned elevated train track is a great place to stroll, see some of the city and the city entrance is behind the Bastille opera. https://janettravels.wordpress.com/2010/06/14/promenade-plantee-turning-discarded-public-space-into-a-pleasant-place-for-parisians/

Thanks for that, Jane! What you’re describing sounds similar to the High Line in Manhattan.

My favorite garden was Les Jardin des Plantes. We also really liked the Jardin de Luxembourg. Both are beautiful.
https://www.jardindesplantesdeparis.fr/fr

2nd recommendation for making sure you hotel has AC for that time frame.

On the sights to see...I'll pose the same question as on your Switzerland question...what sounds like fun to you? Since you mentioned walks, I'd recommend www.paris-walks.com They are an excellent way to have a short guided tour of specific areas or fields of interest.

I've also watched a bunch of walking tour videos by Corey Frye, A French Frye in Paris and RS guide Vero. I often will pull out several things they show and create my own walk thru various areas.

Thank you!