It’s emotional and traumatic to be laid off, and even worse to be fired. You’re out of work, you’re out of a paycheck, and you will lose the bond you have with your co-workers. Give yourself some time to mourn a bit, especially if you loved your job. It’s a loss, give yourself some time and space to grieve.
Then you need to get practical and get over it. The quicker you get a job search up and running, the faster you’ll be thinking about your new job.
See a comprehensive list of activities to get you going here.