Paris airport to Brugge

You should be fine but I believe there is a transfer maybe in Lille so know your routing and schedules well.If you arrive late you could stay at airport hotel at CDG.

From CDG to Bruges, you will definitely need a reservation, since there are only 3 TGV trains/day that head from the airport itself to Bruges via Brussels. There are options from the airport to Lille, then to Bruges, but they also require a reservation to Lille, and involve transferring between railway stations in Lille. The only other option for better frequencies is to catch the RER regional commuter train in from the airport to Gare du Nord, and catch your train there.
Do you already have a pass? If not, consider purchasing a point to point ticket at tgv-europe.com (keep telling it that your location is in Great Britain, and use "Roissy" as your point of departure....CDG will pop up to select.) You could always add 5 or 6 hours onto your arrival time to cope with the chance of any late arrival. Walkup fares would probably still be available, but they'll be about 90 Euro, more than twice the cost of a discount ticket available on the web. The deep discount tickets are non-refundable.

You don't need a reservation in November. Consider taking the RER to Gare du Nord and going on the high speed Thalys line to Brussels. Brugge is quick transfer from Brussels. Trains leave hourly and you can buy the tickets when you arrive at the station.

I would not pre-purchase, as you would be out of luck if your flight is delayed.

Reservations are mandatory on all Thalys and TGV trains. If you purchase a ticket, whether on the web at a discount, or at the station ticket booth, the reservation comes with it. If you have a railpass, you will have to pay extra for the reservation (it's also a supplemental charge for riding on the high speed trains.) With a rail pass, you do run the risk of there not being a reservation available, since national rail companies limit those available for passholders. That would be important if you want to catch one of the few trains directly out of CDG. As mentioned earlier, you can come into Gare du Nord n the RER and have much more success getting a ticket or reservation on the trains leaving from there. But that'll add at least 90 minutes to your travel time to Bruges.

Let me rephrase... you don't need to pre-purchase a ticket in November.