The Passover celebrates when God sent the final plague on Egypt, the death of the firstborn, in order to set His people free. It pictured the day when His own Firstborn would die in order to set His people free.
The Feast of First Fruits recognized God's provision for the Israelites in the Promised Land, but it also looks to His provision of eternal life for us through the resurrection.
The Feast of Weeks was celebrated precisely 50 days from the Feast of First Fruits to celebrate all that God has given. According to Jewish tradition, this time corresponded to the giving of the Ten Commandments to Moses. Just as God provided His Law to the Israelites, He provided His Spirit to guide us in following His Law at Pentecost.
The Feast of Trumpets (Rosh Hashanah) celebrated a new year for the Israelites, a new beginning, and a time of reflecting on their sin and turning toward God. It looks forward to the new beginning God promised in Revelation, after the last trumpet is sounded, when we will reflect upon our sin for the last time before spending eternity with God.
The Day of Atonement (Yom Kippur) was the one day a year when the priest could enter the Holy of Holies, apply the blood of the sacrifice to the mercy seat and make atonement for the sins of the people. It looks forward to the final cleansing of sin, when God looks upon the covering for our sin, Jesus' blood, and perfect atonement has been made.
The Feast of Tabernacles (Sukkot) celebrates God bringing the Israelites out of Egypt. They spent a week living in booths or tabernacles constructed of palm branches to recall the way they lived in the wilderness. This feast looks forward to the gathering of the nations in Revelation 7:9-10, "After this I looked, and behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, and crying out with a loud voice, “Salvation belongs to our God who sits on the throne, and to the Lamb!”
Every part of the Bible tells the story of God's love and redemption of His people through His Son, Jesus!