HR Pros: I'm leaving my comfortable HR nest to take a role as the solo HR person for a different org. Any tips or advice?

Hello!

I recently accepted a position where I will be the solo HR person for an org of about 150 employees. The previous person in the role only served as an admin and they are bringing me on to be a strategic partner. This will be the first time that I don't have a department of geniuses to bounce ideas off of or consult when I'm unsure of something. I am still new in my career, about two years in and I have a Master's in HRM. I am so excited but nervous at the same time. Do you have any advice you can share?