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

It is the first offer in 2 months and I do not want to mess it up. There are 16 people counting on me, so I am trying to be careful. The hiring manager was friendly and open. Did you negotiate?

Thanks for writing this out. I went through something close to it 2 months ago, and it settled down once I kept a simple log of every call and form.