Your first sentence may well be the most important sentence in your entire novel. Here are some first sentences from well-known fantasy titles from Tolkien, onward. Which ones do you like best?
I like the opening to The Summer Tree, The Black Company, The Hobbit, and Voyage of the Dawn Treader the best. The Gunslinger is also good. None of them are bad, in my opinion (and none of the books on this list that I've read were bad, either).
Great Opening Sentences from Classic Fantasy Novels