Back in the 50s 60s when I went to Catholic school if possible we were suppose to show up at Mass on Sunday at a prescribed time and sit with our class. A shirt and tie was mandatory. Though if we were doing something with the family we were allowed to go at a different time as long as we went. I don’t remember anyone going to mass in jeans or t-shirts then.
As a lapsed Catholic, when I do attend now.....I see people dressed from very dressed up to very sloppy. I suppose God does not condemn on that account
My husband as a kid had to sit with his class - this was the Bronx. Jackets and ties always. We never had air-conditioning in church - most of the churches were stone and therefore pretty cool. But if we were caught fanning ourselves, Sister would swoop down with that clicker!