Did anyone get a WARN notice? after 16 years as a marketing coordinator

My employer announced that the site will close and gave us written notice. This is my first time dealing with any of this. I do not know if I should start looking now or wait for severance news. Should I stay for the bonus?

Thanks for writing this out. I went through something close to it 13 months ago, and it settled down once I kept a simple log of every call and form.