It's under Get Info (right click on a pic).
This is a real ground-up rewrite, an Apple tend to strip features out until they are working properly in the new system.
They simply do not fear the "one step back to be able to move forward" approach.
Having said that, I've switched my serious stuff to Lightroom and will use Photos for point=and-shoot fun stuff.
Edited by ian_c (Fri 10-Apr-15 12:33:45)