How to travel by train to Serbia and then Montenegro with family in the spring?

Hi there! We’re planning to visit Serbia (1 week) and then Montenegro (2nd week) with our kids from April 18 to May 4. We’d prefer to travel by train (overnight if possible), but we’re not sure which platform to book on or when to do it (is it too early?). If anyone has any tips, I’m all ears!!

hi, check if the Interrail pass is worth it financially And then you can find the train schedules here