This is one of several New Testament verses describing Christ as the beginning or first-born of God’s creation:
14 “And to the angel of the church in Laodicea write: ‘The words of the Amen, the faithful and true witness, the beginning of God’s creation. (Revelation 3:14)
As such it needs to be considered with the other similar verses, where there is more context to explain what the New Testament writers mean by this language.
The key passage here is Colossians 1, which is the most accessible of Paul’s explanations of the two creations in the Bible – the old creation and the new creation, and Christ’s position as firstborn from the dead, so firstborn of the new creation:
Other answers worth consulting include: