Struggling AP chem teacher

First year chem teacher, need a triage strategy for AP Chem.
I found out I was teaching AP Chem about four days before students showed up. No prep time at all, and it even took admin a few days to sign off so I could get the AP classroom code activated.

I inherited some bare bones materials from the previous teacher, so I’m not starting completely from zero, but it’s thin.

The real problem is that most of the kids in this class never took high school chemistry. I’ve had to stop mid lesson to cover foundational stuff like reading chemical formulas, moles, dimensional analysis, the kind of thing that’s normally assumed knowledge walking into AP. We all left class today feeling pretty frustrated.

On top of that, the section has about 40 students.
Anyone dealt with an AP class where most kids are missing prerequisite content? Looking for a system or pacing approach to get them caught up on fundamentals without completely sacrificing AP pacing. Open to anything: bell ringer routines, diagnostic tools, remediation modules, whatever has actually worked for you.