This is an extremely easy first day of school, introduction and/or warm up activity. It requires no preparation, it's interactive and it's all but guaranteed to work. Playing is simple.
Tell the class 3 things about yourself.
2 of them must be true and one of them has to be a lie.
Have your students discuss what you said and try to figure out which statement was a lie and why. After you finish talking about yourself have your students introduce themselves by doing the same thing.