Until a Route is created, the design workspace is unavailable and the Palette does not display.
A Route is made of two or more components linked together. The properties of each component have to be configured individually, when necessary, in order to function properly.
The way components and connection between them is handled when creating a Route is almost the same as when designing a Job. So, for more information, see Adding components to the Job and Connecting the components together.
For real-life use cases of Routes, refer to Talend ESB Mediation Components documentation in Talend Help Center.