HI this is my first time traveling to Europe. I will fly into Zurich stay there for 4 days and want to take the train to Venice on Oct 6 at night. Should I book train tix on Raileurope? Or will it be possible once I am in Zurich to buy the night train ticket to Venice only 4 days in advance? Will the tickets sell out?
I would recommend that you book the tickets in advance.
I took a similar trip recently and I am glad that I booked in advance because the train was VERY FULL but this was also in July.
You can probably get them at the last minute, but you might not get a bed if that is what you are looking for. And you might not get them for the time that you want. So if you want to book a seat, I say the earlier the better.