Well there are thousands of railways so it’s hard to recommend!

There are plenty of stunning railways in the Alps, Bernina is one of them : https://www.seat61.com/trains-and-routes/bernina-express.htm

Gracias por la respuesta. Que ruta en tren para principiantes recomiendan. Gracias 

This forum is about rail travel. Trains are a fantastic way to travel around Europe : sometimes high-speed, sometimes slow and scenic,… You may get regular train tickets or a pass like Eurail.

Have a look a this link : https://www.seat61.com/how-to-use-a-eurail-pass.htm