There are several options for you:
First the flexible option:
You can book all your tickets at the Railwaystations and there is no need for advanced bookings.
Advantages:
Disadvantages:
- Expensive
- Waiting in line at the counter
The flexible online option:
You can buy your tickets on the go through the ÖBB, SBB and SNCF website or app.
Advantages:
Disadvantages:
- As Expensive as at the counter
Pre-Booking option:
When you are a little bit flexible in your itinary and you book in advance, you can reserve heavy discounts though the following programs:
Advantages:
- Sometimes up to 75% cheaper
Disadvantages:
- No flexibility
- Not all connections are eligable for discounts
Interrail option:
You can buy a interrail pass on the interrail website.
If you are aged between 12-27 the following prices apply:
- 208€ for 5 days in an 15 day period
- 255€ for 7 days in an 31 day period
- 305€ for 10 days in an 31 day period
If you are aged between 27-59 the following prices apply:
- 269€ for 5 days in an 15 day period
- 320€ for 7 days in an 31 day period
- 381€ for 10 days in an 31 day period
Advantages:
- Cheap for long travels
- Flexible
Disadvantages:
- Expensive for short travel