Hello /trv/. I'm an American who's traveling to Europe this summer, and I have a concern. I'm 19 years old and a freshman in college, and this summer, I'll be going to Croatia with my best friend from high school. My friend is of Croatian descent, and as such, he has family over there, and thus, he will actually arrive in Croatia a few days before me. Also, since I'm a starving college student, I couldn't afford a direct flight to Croatia. Instead, I booked a flight to Frankfurt, Germany, and I plan to take a train into Zagreb.

However, when I try to look online for train tickets, there are so many different websites with different prices and fees, and I'm quite confused on what do to do. The last thing I'd want is to get stranded in a foreign country (I can only speak English, Spanish, and very basic German).

My itinerary thus far is:
>Depart San Francisco on 6/20, at 13:20
>Arrive in Keflavik, Iceland at 4:40 on 6/21
>Depart Keflavik at 6:40
>Arrive in Frankfurt, Germany at 11:45 on 6/21

And then from Frankfurt to Zagreb, it appears that I'd have a 7-11 hour train ride, with a transfer in Munich. How would I go about getting a good deal and making sure I'm on the right train?