The narrator of "Stopping by Woods on a Snowy Evening" is not the focus, and so little can be inferred about him by the text, assuming he is not simply Robert Frost himself. The narrator is traveling in pursuit of a goal, either personal or business, and cannot take much time for himself. He is traveling by horse, but the only description of the horse is that it is "little" and has "harness bells," which could mean the narrator is riding the horse, or the horse is pulling a cart. The destination is far away, with "miles to go," and the narrator will probably not be stopping to rest. He may live in the immediate area; he thinks that he knows the owner of the woods who lives in a nearby village, so he is either a resident or a constant visitor. Also, the narrator may be female; there is no indication either way.
The only concrete thing known about the narrator is that he is on a long journey and that he must focus on his final goal:
The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep.
(Frost, "Stopping by Woods on a Snowy Evening," eNotes eText)
The narrator's promises cannot wait, and he cannot take time for himself before fulfilling them.