Thornfield is imposing from the outside and Jane is intimated by its looming presence, but when she enters, she finds it not as bad as she'd feared.
This description of her initial entry to Thornfield is found in Chapter 11, about two-three pages in, in my text:
"...the driver got down and opened a pair of gates: we passed through, and they clashed to behind us. We now slowly ascended a drive, and came upon the long front of a house; candlelight gleamed from one of the curtained bow-window; all the rest were dark.
"Will you walk this way, ma'am?" said the girl, and I followed her across a square hall with high doors all round: she ushered me into a room whose double illuimation of fire and candle first dazzled me, contrasting as it did with the darkness...when I could see, however, a cosy and agreebale picture presented itself to my view.
A snug small room; a round table by a cheerful fire; an arm-chair, high-backed and old-fashioned..."