We use Roku and Netflix all the time. It can be intimidating at first with so many selections. What got us really started is that we spent 5 months without cable and all we had was the Roku. If we wanted to watch TV that was it. I absolutely love the British shows, especially the mystery ones. They are so well done. If you like that try Foyle's War, Murder in Paradise, Last Tango in Halifax, Call the Midwife, to name a few.
You can search by genre and once it figures out what you like to watch it will make suggestions for you as well. We rarely watch network TV anymore.