I think it just depends on what you already like, but Stephen King, while hit or miss for me, is a pretty accessible place to start. Other than that if you like more serious literary fiction I would recommend any of Shirley Jackson’s books or Toni Morrison’s Beloved. Both are gothic fiction so they’re going to be more atmospheric than anything else. I saw you replied to someone’s else you like nonfiction so Carmen Maria Machado’s In The Dream House, which uses the haunted house framework to tell the story of an abusive same sex relationship the author was in, might be interesting. And if nothing else, pick up some goosebumps or point horror. They’re teen horror and a bit campy, but still fun and where a lot of us started.