The feasts of Passover, Firstfruits and Pentecost have already been fulfilled in the death of Christ (our passover Lamb - 1 Cor 5:17), His ressurection (1 Corinthians 15:20 & 23, Acts 26:23) and the coming of the Holy Spirit (Acts 2:1-4), so it is unsure how we are to celebrate them now that they are no longer a shadow, but we have the reality.
Some people believe that the feast of Tabernacles/booths was fulfilled, at least partially, by the Transfiguration - when Elijah and Moses met with Jesus. This explains why Peter wanted to make Booths for the them. (Matt 17:1-13; Mark 9:2-13; Luke 9:22-27)
Personally, I am very much looking forward to the fullfilment of feast of Trumpets - Maranatha!