Help with Train Commute

Good day lovely people. I am a first time traveller to Switzerland. I am completely new to the train networks of Europe and would be grateful if you all could help me out. I have read a lot of advices online on railways which has got me more confused so I decided reddit would be the best place to clear off my doubts. I am going to risk it by giving few specifics of my travel. I will be at B&B Hotel, Helblingstrasse 9, Rothrist, Switzerland on the 26th of November, I need to be in Milano Centrale Railway Station, Italy before the 5 PM of 26th. Requesting you all to guide me on which train to book from Rothrist with the minimum numbers of change in trains. Thank you all