It’s more an ‘expansion’ than ‘explosion’. The term ‘Big Bang’ was first used to clearly distinguish the model from the steady-state cosmological model. The term does not refer to a disordered explosion.
It also wasn’t necessarily the ‘beginning’. We have no way of determining what happened before that, or if ‘before that’ is even possible. But there are various hypotheses including several wherein it is not ‘the beginning’.