This is an interesting poem, where Frost, probably on a walk, looks at a snow-covered field, and how everything his hidden and smothered by the snow. He makes a comparison between this, and between the "desert places" in his own soul, the empty, barren, featureless places in his heart where he has buried something, covered it up in order to not have to think about it.
It doesn't mention why he entered the woods, or was out walking on a snowy afternoon. He mentions "loneliness" and being "absent-spirited", so perhaps, in a fit of loneliness and restlessness of spirit, he took off on a walk to distract himself and to stay busy. As he walks though, the
"blanker whiteness of benighted snow/With no expression, nothing to express"
reminds him of his own life, and how he, like the field, has his own memories and experiences that he has covered with a cold blanket so as to not think about them. He states:
"I have it in me so much nearer home/To scare myself with my own desert places."
He says that the empty field, the "empty spaces between stars-on stars where no human race" exists, doesn't scare him as it might some people, because he has those same vast spaces in his soul.
I hope that those thoughts help! It's an interesting poem; good luck!