That statement alone is heretical. The Son of Man - Jesus - was not "generated before creation", he is the eternal God. He was the creator himself. Referring to Christ as a created being is as heretical a statement as any book purporting to be scripture could make.
The book is loaded with heresy. If one is determined to believe it, knowingly or not, they are committed to not believing the Bible. The 2 books are at odds in countless ways. At one point Enoch endorses the pagan practice of worshiping the weather. Obviously, the timeline showing Enoch could not have been contemporary with Noah, for which there is no accepted alternative timeline, alone shows its in-authenticity. Also, Enoch refers to his 500th year, yet scripture specifically tells us all his years were only 365. The Bible says the Great Dragon, Satan, was responsible for deceiving the world, Enoch says it was a being named Gadreel. He also attributes all sin to an angel, Azazel, the Bible tells us that Adam's sin, was the source of sin.
There are all sorts of unbiblical, directly contradictory teachings in Enoch, angels building the ark, rain before the flood, etc. It condones prayer to angels, strictly forbidden in scripture, claims angels are an intercessor between man and God (when the NT tells us repeatedly that the only intercessor is Christ) and perhaps most revealing of all, it is horribly written, as though it were written by someone childish, unlearned, or completely ignorant of the things of God, and as more than one theologian has pointed out, is written in the manner and fashion and wording of someone who would have lived in the 1st or 2nd century BC, not the ancients from thousands of years before.