Delta likes leadership and community service experience. See if the position of the president of your homeowners association is opened! Scouts, Pilots for kids etc. Be sincere about it and catch the fire. If you fake it - they'll notice it and you are toast.

Lumosity.com for brain prep.

Having someone on the inside see the hiring manager is of course a plus, but overrated - very few had done it.
You CAN get hired by Delta without knowing anyone!