Unless things have changed, and who knows with Amtrak, but with most firms, if they require you to travel, or overnight on company business, then you can usually count on them taking care of the transportation, meal voucher, and lodging. There are exceptions of course, but those are usually spelled out in your employment contract.
Welcome aboard! And remember the mantra, (that has been so sorely forgotten at Amtrak) "The customer is ALWAYS right" (even when they are wrong)
Also, as with any company, you will run into fellow employees who will show you how to "cut corners" (closing cafe early as an example, or not making beds for customers, or not helping with luggage, yada, yada, yada) DON'T LISTEN, politely pretend to listen, and then do your job as you have been instructed, and serve your customers how You would like to be served.
There are many, many, many fine, and even excellent employees at Amtrak. Unfortunately we only usually hear about the bad apples. Be a shining star.
There, I'll get off my soapbox now.