Christmas 2023 in Paris. Transport pass recommended

depends on what you need it for but basically no pass works for this time period. What you want is a Navigo Easy card on which you can then load carnet of 10 t+ metro bus tickets at a discount. You can also load day passes. If you plan a trip out of Paris in the Ile de France, you buy point to point RER tickets including from CDG to Paris.

Thanks Janet
That’s what thought would be best strategy. Any ID needed (face pic) at point of purchase. Plan on RER from CDG

No i.d. is needed to purchase a Navigo Easy or to purchase individual tickets.

There are no electronic tickets for the RER. The Easy card can be loaded with a day pass, usable on the RER with the proper zone coverage. Otherwise, RER tickets are paper.