Had this exact problem when I tried to get into horror last October. Jumped straight into something like 'The Stand' and it was way too much. Eventually I learned you need a hook beyond just scares. Grady Hendrix is my gold standard for beginners because he blends humor and horror. 'My Best Friend's Exorcism' is basically an 80s movie in book form. The supernatural stuff is there, but the real heart is the friendship story, so you get invested before the creepy stuff ramps up. Shirley Jackson is another solid pick, 'The Haunting of Hill House' is more atmosphere than gore, which is perfect if you're not into splatter. Her prose is so precise and unsettling, it creeps under your skin slowly. The new reader mistake is thinking horror equals monsters and gore, but often the best starter books are about a slow-building dread you can't shake.
Tana French's 'The Searcher' isn't strictly horror, but the isolated Irish setting and the mounting paranoia scratched that itch for me in a more literary way. Sometimes crossing over from a genre you already like, like mystery or thriller, can ease you in. Find an author who writes in a style you enjoy outside of horror, then see if they've dipped a toe in. Makes the transition less jarring.