katharina,
Welcome to the Forum!
Relax. I would not fly to Paris ONLY to buy hiking poles! You can EASILY buy hiking poles when you arrive in SJPdP. They are available at these two boutiques owned by the same helpful veteran pilgrim;
Boutique du Pelerin, 32 rue de La Citadelle and
Direction Compostelle, place Floquet. Here is their French web >>
http://directioncompostelle.com/directi ... ments.html
For your journey to SJPdP it might be SIMPLER to fly direct to Biarritz, then take the airport bus to the BAYONNE railroad station (Gare SNCF) to get the local TER line 62 train to SJPdP. This train cost roughly 10 euros. There is no need to reserve; seating is open as on a tram or metro. SJPdP is the last stop.
Nevertheless since you asked here is some basic info regarding trains from Paris to SJPdP..
There are many trains each day from Paris to Bayonne and SJPdP. You can see schedules up to 3 months in advance at this SNCF (French National Rail Road ) link.
http://www.voyages-sncf.com/.
1. There are trains that depart from CDG airport. These are SNCF TGV (Tres Grand Express) from CdG Paris 2 airport to BORDEAUX and which then connect with another TGV to Bayonne and a TER line 62 train from Bayonne to SJPdP.
2. The route is generally a TGV train from the Paris Gare Montparnasse to Bayonne and then a regional TER line 62 train from Bayonne to SJPdP. Generally there are 4 TGV trains to Bayonne from Paris Montparnasse each day and many TER line 62 trains from Bayonne to SJPdP.
3. If you wish you could take the regular overnight train from Paris Gare Austerlitz to Bayonne to connect with a morning TER line 62 train to SJPdP.
Prices vary by your age, the type of train and how far in advance they are booked. You NEED a reservation for any TGV train and it is cheaper to book the ticket well in advance; you do NOT need a reservation for the TER line 62. You can buy tickets on-line. However you can also book everything with a live clerk at the station the day of departure if you wish. If you take the mid morning train from Paris you can be in SJPdP by late afternoon.
Bon Voyage and Buen Camino,
Margaret Meredith