Standard English is a variety of the English language that is accepted as the usual correct form. This dialect, as opposed to all the Nonstandard English dialects, is widely used in formal settings, by the governments, the media, schools and for international communication, so since it is used in a variety of occasions English Speakers should learn it so they can communicate better and with more people and avoid misunderstandings.
The author is giving details and purpose to this event and is inviting people to come to attend it. They even tell you how you can get to the event and about the designated "drop zones".