Just got laid off, what should I do first? after 16 years as an event coordinator

I lost my job as an event coordinator and I am not sure what to do first. I have read a lot of threads here and could not find my exact situation. I have a box of my things and a short letter about benefits.

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.