Hello rileynicosia
Thank you for your query.
The first thing I want to point out to you is that we also have an English platform in the community. You can get to it by switching the language to English.
You can find the area of validity of the Swiss Travel Pass under the following link: Map “Area of validity Swiss Travel Pass”. (mystsnet.com)
On the app you can enter your desired connection. There are some private railroads where you have to pay a surcharge. You can see this on the app.
I wish you a nice day.
Kind regards, AferditaH