I know 2.8 is not yet released.
However I am at the limits of what blender 2.79 can do. So I wonder how to set the recent 2.8 builds into cycles mode?
As of april 2018 the top bar is still work in progress, as most of blender 2.8, so this answer might be temporary or might make no sense at a later date.
The render engine has been moved (at least for now) to the scene section of the properties window.
It is hard to know if this change will be permanent, as 2.8 has not been released and it is constantly changing.
Tomorrow might be in a different place... who knows.