First Time Business Acquisition

I am a self-funded searcher, just a couple of weeks away from closing on my first business acquisition. As a first-time business owner, I’m finding it challenging to grasp what needs to happen on Day 1—things like transferring bank accounts, insurance, and other essentials to the new entity feel overwhelming and unclear. Could someone offer guidance or, ideally, provide a checklist for the first week to outline the key steps I should take?