How do I set up a Dell S2725HS monitor with my MacBook Air using a trackpad or mouse?

I bought a dell monitor Dell S2725HS 27 Inch Monitor, to use w my new MacBook Air. I can connect the MacBook Air to it but the monitor is showing a set up screen "Please select, English" and I am unable to use my trackpad or mouse to do this monitor set up? Any advice?

[Re-Titled by Moderator]

Original Title: Unable to use