Ответ:

Hello, my friend! I want to invite you to my  hallowe'en party! There will be a lot of food games, and activities! If you don't have a costume, don't become upset, I will give you one. After the party, we will go trick or treating. Only 100% fun! Waiting you at my house at 31 October, 6pm!

                                                                                              Yours, Ben