Do you know how to delete hangout contacts? Not hiding or blocking them, but removing them forever.

I can't find anything on Google but I have some contacts from when I contacted people from hpf on hangouts and im so worried bc I don't want my parents seeing pls help

Also do u know how to remove a group chat or space? I blocked them but I can still see them

I really don't want my parents finding hpff and I really don't think there's any way you can so I really want to complain to Google and tell them to have a way to do this but I also don't want to

I don't think I used a single period here but if feels so go good type that and I'm legit crying I've missed hpff so much and if anyone has my email please delete it