I'm goin to catholic high school next year. people say that catholic H.S is harder than public. is this true?

i am a 13 year old kid who is joining a catholic high school next year. I come from a public school and all my friends/family say that the transaction from public to catholic schools is very strenuouss. They say that you have to work a lot harder to pass at a catholic school and that catholic schools are more challenging than public school. I want to know if this is true and if it is, how much harder would it be. Also, I am a straight A student who doesn't study that much. Futhermore, what challenges would I face (be specific please)