DB Bahn
 

I bought a train ticket from Stuttgart to Munich on the DB Bahn website. My wife and I are supposed to be in first class (it was like 10E more). They emailed me an "online ticket" but there are no seats on it. It just says to bring my American Express with me. How do I know where to sit? Will they assign us seats before we travel? Do we have to exchange the "online ticket" for a real ticket at the station? I'm just confused. Thanks in advance!

Under the "Reservierung" column in the PDF, does it say anything about Sitzplätze? IME, most first class tickets nowadays come automatically with seat reservations, which would read something like "2 Sitzplätze, Wg. 29, Pl. 41 42, 2 Fenster, Tisch", which indicates you have seats 41 and 42 in car 29.

If your tickets don't indicate anything along those lines, you can reserve seats for €4 each on the website, or just get on the train and find seats that aren't marked as reserved.

... in 1st class usually there will be ample choice of seats without reservations to choose from. Outside the busiest hours like Monday morning or Friday afternoon probably 50% of the seats will be available/not reserved.

You can reserve online, or with any of the red/white ATMs that you find at any station with DB service. Reservations for ICE trains can be made up to 10 mins before departure.