Meals

What are the requirements for the weekly Shabbat bread as far as the kind of bread and how it is made?

My boyfriend and I recently moved to a new apartment. Most of the people who live are Orthodox Jews. We are not Jewish and feel somewhat out of place here. We want to be wanted and to get along with our neighbors. One Orthodox couple here has welcomed us as neighbors, went out of their way to greet us and made us feel at home here, and now they want us to join them for a Sabbath meal. They seem very open minded and are interested in being our friends.   But we have no idea what to expect at a Sabbath meal. We are nervous about accepting this invitation. We would like to know is there anything special we should do? What should we say to them? What type of food can we expect them to serve? How can we reciprocate? They told us to wear whatever we want, but seriously, should we dress any particular way?

What are the proper Laws and Customs of a Shabbat meal on Friday evening?