Just got laid off, what should I do first?

I lost my job as a data-entry clerk and I am not sure what to do first. There are 18 people counting on me, so I am trying to be careful. I have a box of my things and a short letter about benefits. Which steps were urgent?

Thanks for writing this out. I went through something close to it 10 months ago, and it settled down once I kept a simple log of every call and form.