First,you should be on time.There's no doubt that it's impolite to let others wait for you.Instead,it's better to arrive a little earlier,which not only means you feel glad to be invited but also show your respect.
Second,you are not supposed to be too shy.Parties are the place where everyone get together to have fun.Thus,you are expected to spend your enjoyable time just as you like.And then you'll sense the true happiness because of the party.
