Offer arrived, can I still ask for more? - any advice?

I want to negotiate but I am afraid they will withdraw. This is my first time dealing with any of this. The hiring manager was friendly and open. What wording worked?

Ask about the range, not a number on its own. It felt more collaborative.

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.