re: Planning a first trip to Paris, is it bad to go solo?

Book direct with whatever airline hits your pricing point. If you check Google Flights, you'll see that RT prices from MSY with Friday departures can be as low as $672 during Jan/Feb.

I'd choose a route that flies through DC/Dulles over O'Hare/Chicago, Montreal or Newark, simply because weather delays are less likely thru IAD.

After arriving, we looked into bus tours out of Paris and ended up booking one to Normandy and WWII areas. It was a full day, starting very early, but had some of the most memorable experiences. Went to the museum in Caen, La Pointe du Hoc, the American Cemetery, etc.

We did another bus day-trip to Monet's home and gardens. That was also excellent.

I would go there by myself in a heartbeat. I can cover a lot more ground when traveling solo, and can go see odd stuff that others might not want to visit.