Laid off this week, where do I start? after 16 years as a social media manager

I was let go as a social media manager this week and I am still in shock. There are 16 people counting on me, so I am trying to be careful. I have a box of my things and a short letter about benefits. Is there a checklist I should follow?

Ask for your final pay, unused leave and any documents in writing before you leave, if you still can.