So, here is a list of festivals and deities I found some info on.
Egyptian Deities (I'd make all the following Patron Deities either for Kemetic or some only for a Greco-Kemetic Religion)
Amun
Atum
Bes (Fertility Godess)
Geb
Hathor
Horus
Isis
Khnum (Potter God)
Nut
Osris
Ptah
Re
Sachmet
Seth (Seth-Typhon for Greco-Kemetic)
Serapis (Greco-Kemetic Only)
Shai (more important in Greco-Kemetic, corresponded with greek Agathos Daimon, snake headed pig and fortune telling deity. Earlier deity of only fate and more of an abstraction until the greeks came in)
Shu
Sobek
Tefnut
Thoth
Festivals
Amesysia: Late July and August, celebrating the birth of Isis, popular festivitivities of lighting lamps
Amun Festival of the Valley: Held in May, procession of Amun's barque from Thebes to the western tombs
Besia: Celebrated the protective and fertility godess Bes, festivities included processional Bes-masking and the preparation of breads and drinks in celebration of the deity
Harpocrateia: Held in January, celebrating the child form of Horus, Harpocrates, associated with military prowess. Celebrations included preperation of sweet foods and exchanging of gifts
Isia: October through late November. The symbolic re-eneactment of the morning and search by the godess Isis for the dismembered body of Osris. a Gilded Cow is processed before the priests and water is poured over a container of earth shows the renewal of cultivation as the Nile recedes. Festivities included prepeartating of cakes and breads and celebratory responses during the drama.
Khnum Festival of Esna: Paired with the festival of Raising the Heavens, held in winter celebrated Khnum's creating of the cosmos with his wheel. Festivivities included processions across Egypt, masking, protective chants and invocations of Khnum's creative acts for human procreation
Kronia: Late Sepember through mid November. Celebrated the birth of regional deities, espicially Sobek. Festivities seemed to mirror Saturnalia and the festival seemed o be imported from the Greeks.
Min: Celebration of the begining of the grain harvest
Navigum Isidis: Held in early March celebrating the reopening on the navigation of the Nile, religous connection is it also was the festival of representing Isis as piloting Osris's funeral barque. Festivities of this included processions culminating in the launching of a ritual barque representing the boat of Isis.
Nehebkau: New Year Festival, celebrated in July, commemorating the rebirth of vegetation, festivitivies included mutual gift giving and special sacrifices in the temples.
Opet Festival of Amun of Karnak: June, the Barque of Amun goes south to Luxor, Festivities included elaborate processions, espicially by boat through the city. Elements of the festival lasted until at least the 1100s where the commerative barque was still being processed through the city ritually.
Sarapia: Greco-Egyptian espicially. Serapis. Mid-March and mid-November. Festivities included, processions with masking, wine labations, sacrifices of bulls and pigs and purification acts. Had royal, oracular and military overtones.
Shai Festival: (Still commerotaed in the early 400s CE) Celebrated the Egyptian deity of civic fortune and domestic protection. Popular festivities included lighting of lamps in homes.
Sokaris: Held in November. Celebrated a form of Osris assocaited with fertility. Festivities included breaking of the Earth, the making of and burial of a corn mummy and procession of the barque of Sokaris
Typhonia: Greco-Kemetic. Honored Seth-Typhon as a protective deity
Wagy: September? A funerary feast associated with the pilgrimage to Abydos
Isia could also be enabled for Hellenic as it was also commemorated in Rome.