Werepyre13, why are you so defensive? Do you really come in thinking that anybody here would tell you that Nyx was not a real goddess? Why would anybody here do that? From what I've seen, we're all very accepting and interested in all sorts of mythologies.
All that said, the followers of Nyx were a very private, very mysterious group. However way that they used to conduct themselves, most of that is lost to history and antiquity. So...nobody really knows how to traditionally work with Nyx or what offerings should be given.
In a situation such as that, I would just meditate upon the concept of night because Nyx is a goddess of the night, and follow your personal gnosis.
You don't "summon" a Goddess, that would be very impolite. You "invite" her to be present. Whether she wishes to come is up to her. You can invite her by simply talking to her as you would an important persona and ask if she will please attend you.
Here I have sited a ritual done for Nyx, or Nox. I don't know if this is completely helpful, but I thought it may give you an idea of how to commune with her. She is the goddess of night, and darkness. Associated with Hecate or the underworld. She is part of Greek Mythology and is usually pictured with black wings, and shrouded in mist. I hope this helps!
Ovid, Metamorphoses 7. 192 ff (trans. Melville) (Roman epic C1st B.C. to C1st A.D.) :
"When she [Selene the Moon] shone in fullest radiance . . . [the witch] Medea . . . went forth alone upon her roaming way, in the deep stillness of the midnight hour . . . Then to the stars she stretched her arms, and thrice she turned about and thrice bedewed her locks with water, thrice a wailing cry she gave, then kneeling on the stony ground, ?O Nox [Nyx the Night] , Mother of Mysteries, and all ye golden Astra (Stars) . . . and thou, divine triceps (three-formed) Hecate . . . and thou, kindly Tellus [Gaia the Earth] , who dost for magic potent herbs provide . . . and Di Omnes Noctis (Gods of Night), be with me now! By your enabling power, at my behest . . . the deep earth groan and ghosts rise from their tombs. Thee too, bright Luna [Selene the Moon] , I banish, though thy throes the clanging bronze assuage; under my spells even my grandsire?s [Helios the Sun?s] chariot grows pale and Aurora [Eos the Dawn] pales before my poison?s power."