x11 wont run by opening or by opening app. Is there a non hacker method to start and run x11?

I've downlowaded Kerkathea to render sketchup models, but cannot open the application. I've followed instructions to install x11 to run the application, but x11 wont run by opening or by opening app. Is there a non hacker method to start and run x11, or should I plan to learn code to enable x11 to run at startup?