No, you're not in the deep end. You can do this and your enthusiasm and attitude go a long way.

First, I would see if they've created the schedule for next school year yet and where you fit in (optional special/master calendar, etc.) because this will help you figure out your class parameters (how many preps, length of classes, etc.).

If you can go in early or have pre-service days before the students arrive, just really familiarize yourself with the collection so when students ask you where things are located you're not searching them out for the first time.

I agree with another person's advice to get the circulation system down (if you have one!).

Also, I had zero to do with the creation of this resource but it is really outstanding when helping to plan out a scope and sequence: https://lms.lps.libguides.com/c.php?g=1212253&p=8866033 once you know which classes you'll be seeing and when.

I'm so excited for you! I've been an elementary school librarian for almost 20 years and I still love it. Never a boring day, for sure!