How do I enter test case steps and expected results?

You can capture as little or as much detail as you wish. TestRail supports either entering test steps and expected results for test cases via simple text fields (the default configuration) or you can enter test steps separately in a more structured way, including preconditions, expected results, and actual results. Learn more in the TestRail User Guide: http://docs.gurock.com/testrail-faq/config-steps