Need help....

there is an autistic boy I know who has a crush on me, and I don’t quite know how to softly explain that Im not interested in dating. He texts me almost nonstop and follows me in the hallways at school, and he even sometimes straight up walks into my class during a lecture to say hello. I don’t know how to politely tell him to stop because i don’t want to hurt his feelings. i don’t have any experience with autism, so please don’t say negative things because i’m not sure if there’s a certain way I should handle this or not. any advice helps:)