Do you know when the Bible came into existence? It was officially canonized through a series of councils at the end of the fourth century and beginning of the fifth, which were convened by the Catholic Church. The Bible is does not inspire itself.
For a second, let’s assume that the Bible isn’t inspired. Alright. Since the Gospels were written so shortly after the life of Christ, they are likely historically accurate (that doesn’t mean they’re necessarily inspired). These four documents–the Gospels–attest to the fact that Jesus established a Church. So, that Church would then have the authority to proclaim which documents are inspired and which aren’t. And it did, which is why you now have a Bible.