@MaryB83
https://www.bcna.org.au/understanding-breast-cancer/types-of-breast-cancer/Hopefully this will help trigger some questions for you. If you have someone with you it will help but you will find the specialist will initiate the conversation and with the information they give questions will come.
Not sure what Specialist you are seeing, Breast Surgeon, Oncologist, Radio et cetera
If you are to have a Mastectomy or lumpectomy here's a link from the main website
https://www.bcna.org.au/understanding-breast-cancer/treatment/surgery/types-of-surgery/Hope that helps