one of the things you are required to do as LU students is to attend their chapel services.
It will be hard for you to attend LU especially as an atheist,
but I know many people that r nonbelievers who still go to LU
(many international students are not christians especially)
As some who goes to a Catholic high school with friends of secular/other faith backgrounds I can definitely say there are some good Christian schools out there that aren’t as “pushy” about their beliefs. My advice is to look at schools with secular clubs/majors involving other faith traditions. One of the schools I’m applying to, Villanova, is Catholic (so not a big drugs/drinking campus) but also is a very welcoming environment, and they offer some nice financial aid if you apply early action. I recommend you check them out.