Waiting rooms are usually closed at night. Be aware that you'll need 2 pass days for this journey.

The direct TGV into Switzerland has a very expensive fee : 37€ 2nd class or 70€ 1st class. It is recommended to avoid it and take any TGV to Strasbourg or Mulhouse : limited 10€ fare, then 20€ until the train is full (both classes). You then cross the border on a TER regional train to Basel.

I'd recommend to find a hostel for the night either in Basel, Zurich or Chur.

Hi thibcabe! Thank you for the response. My mother wants to ride the Glacier Express that’s why we were thinking of taking a train from Paris to St. Moritz. Then St. Moritz to Zermatt via Glacier Express. We plan on purchasing the Eurail Global Pass as well. Or is there an easier way for us to try the Glacier Express from Paris, like what city in Switzerland can we go to?

If you want to stay in a warm place without paying for an expensive hotel/hostel, then go to Zürich airport. Free toilets etc and next morning you can go for the Glacier Express 

The Glacier Express has a 49 CHF seat reservation fee which can sell out weeks in advance. I'd recommend to take the hourly reservation-free regional trains on the same route.

DAY 1 : Paris - Strasbourg - Basel - Landquart - somewhere in the Engadin Valley if you want to take the full route. Otherwise you'll do Chur - St. Moritz twice

DAY 2 : Engadin Valley - Reichenau-Tamins or Chur - Disentis/Mustér - Andermatt - Visp (- Zermatt)

You could also stop for the night in Chur and not do the full route

Thank you for the suggestions MartinM and thibcabe!

Sit back, relax, and enjoy the scenic train ride from Zurich to St. Moritz. The journey takes approximately 2.5 to 3 hours, depending on the train and any transfers required. Arrive in St. Moritz: Once you arrive at St. Moritz, disembark from the train and proceed to your accommodation or explore the beautiful alpine resort town. It's advisable to check the train schedules and availability in advance, as they may vary depending on the season and day of the week. You can visit the official websites of the French National Railways (SNCF) and Swiss Federal Railways (SBB) to find the most up-to-date information on train connections, fares, and schedules.