I’m meeting with missionaries tonight

So I’m genuinely curious about all religions and enjoy learning about them and other cultures. Last night I looked into the church or Latter Day Saints and they’re now having me meet with them at their church. I’m not sure what to do cause I was expecting them to come to my house like they do on tv. I smoke cigarettes and drink quite often and drink coffee and tea etc etc, would they kick me out for that because I do want to learn. I also want to know how they would react to me asking why they believe in the Book of Mormon which is from my understanding written by a man who got stuff from modern day health claims like people being against tobacco and alcohol and so on and so fourth.