To see your workflow application, you'll need to click Publish. The 'Publish Application' link is available from anywhere in WorkflowFirst - just by clicking the "Quick Publish" button at the top. You can also access it from the 'What Next?' list, or the Publish button on the application record.
Once you've published, you'll be given a link to click to open up the application in another tab. It'll probably look pretty bare-bones to begin with:
A couple of things to note. Firstly, you can start your workflow there by clicking the action button, in this example "Enter Vacation Request". This will create the workflow record and start the workflow.
Secondly, you'll notice that you're logged in as "admin". This is the default for WorkflowFirst applications, just to help you get started. But you can easily create users and assign roles to them, and have the app force you to login - we'll get to that in the next section.
Next Topic: Setting Up Users
Please post all questions on the support forum. Thank you.