Read and starred states can both be changed while viewing individual messages, or in bulk from the inbox. Make a bulk selection by tapping the lefthand icons. The envelope icon on the toolbar will toggle the messages’ read state. Add or removing stars (ie favourites) can be done by opening the menu and tapping Add/Remove Star.
Tapping each star in this view will toggle individual messages. While viewing a single message, the read status toggle can be found on the toolbar; the star status is found to the right of the email header, next to the reply icon.