Is this to be used with a gui or the command line? Let's say you will make this to be used from the command prompt. You'll need to make up a menu that the user can access to select options.
You have to do some dreaming/imagining of how you might set up your classes.
You need to provide for "informational and ticketing" in your "system" with the specific need to allow the user to get "details of destinations, timetables and cost of tickets".
So the menu in the user interface (menu at the prompt) will have options for "destinations, timetables and cost of tickets." When the user selects one of these you will need to have a way to call up the requested information from your file(s). Since the main categories of the "system" are "informational and ticketing" you might consider separate classes to deal with these.
These are some preliminary thoughts. You have to start with something easy and feel your way through as you go along, like walking into an unknown forest for the first time.
To help you get started consider something like this:
class for the user to access/enter data
public static void main(String[] args) {
// start with your menu in here
}
class to search_for/book reservations ("ticketing")
class to read files into a data structure(s)
("information") that you can use in your user class
You have to try different things to find what will work for you. This is where the lessons on objects and object–oriented programming come to play.
Do one thing at a time. Start with the menu. As you are working on this new ideas will emerge.