i have recently started with sheep, i have 3 2month old orphan lambs, my ones will be eaten as soon as they reach a suitable age and size. If you intend to eat the sheep then they will need supplement feeding hay, pellets etc.
I think sheep are almost easier to keep than pigs, though others may differ.
Sheep are hardier than you think, so getting six on the change that some die i think is someone trying to make money. My three lambs survived the snows no problem.
There is tonnes more information in the sheep section, and also farm more experience owners than me who will give you more and better advice.