Yeh, it is hard to get used to call by first name

I call my stepdad by his first name. I go by dad when writing a birthday card or Christmas card(that makes him very happy). I call his parents by grandma and grandpa. I call everyone in my church by first name no matter how old they are. I never need to call my bf's parents. Just say, "hey, how are you". I wrote their first names on their gift. My bf said it is ok. I personally feel that Mr and Ms are too formal. I know it is strange that Americans are so casual about names. Don't trouble yourself too much. They probably just don't care.