Want to go to Pairs from Amsterdam by train...any suggestions on how to do this?

Thalys is the name of the high-speed train service that connects the two cities.
Schedules fares and tickets can be had here: www.thalys.com
High-speed trains use airline style pricing so the sooner you book the cheaper it will be.

We're doing Amsterdam to Paris on Thalys in early July. Ordering tickets was a breeze on Rick's site. https://ricksteves.raileurope.com/us/rail/point_to_point/triprequest.htm

We ordered tickets in late March for $42 per person. Now they're up to $150 for the same thing. Yikes!

Another website is trainline.eu. It's about a 3h30m ride Know the name of your train station in Paris and book early to get better deals. Enjoy
Princess Pupule

If you are planning on taking the train to Paris directly from Amsterdam airport, be careful. Those deep discount tickets are nonrefundable, and if your plane is late and you miss the train, you have no recourse but to buy a new full fare ticket, which won't be cheap. Ideally, you should spend a night in Amsterdam to be certain you'll make the train you get tickets for the next day so you are very sure of making it. Buy the return ticket will be safe.

you should spend a night in Amsterdam to be certain you'll make the train you get tickets for the next day so you are very sure of making it
Sound advice. And I wouldn't be happy with the prospect of another four hours of travelling after a long flight.

Thalys is a pleasurable train to ride.