My husband and I will be spending a few days in Paris in early May. We are open to the area that we stay in and need guidance. We would like to stay in an area with cute cafes, romantic, and walk-able, easy to explore. We prefer charming, perhaps quaint if that's a good word, instead of fancy. We would like a location close to Metro so we can navigate the sites. Walking some distance is fine with us. Do you have suggestions for a certain Arrondissement based off those thoughts? Thank you in advance!
My favorite neighborhood of all in Paris is Ile St. Louis (4th) which fits your description perfectly. It's the little island next to the island where Notre Dame is. It's the very heart of Paris, charming, romantic, quaint and surrounded by the river and amazing views. Lots of wonderful restaurants, cafes (my favorite is La Flore en l'Ile by the pedestrian bridge at the east end), fun shops. ISL is like a little village. It's so easy to walk from there along the river and to many places you'll want to go. There's also easy Metro access at Pont Marie or St. Michel. Busses on the island or very close by.
My next choice would be anywhere in the Marais (3rd/4th), Latin Quarter (5th) or St. Germain (6th). As close to the river as possible.
Especially for a first visit I like the 4th, 5th and 6th. The closer to the river the better. That will keep you in a central area, walkable to many places, with plenty of cafes to choose from.