Get your resume ready. Start applying for other jobs just in case. You can always turn down interviews or offers if you get to stay.
I've never been in a layoff but I have several colleagues who came from a company that was completely shut down. Most of the people from that place found new jobs pretty quickly, some of them just took whatever they could find and in the meantime applied for other things. They got a couple of months severance depending on how long they'd been with the company. So I guess they managed the layoff pretty ok. Some of them had to work right up until the end, they were supposed to be archiving things on the last few days before closing but people just sat around in limbo, not having anything to do but also not getting to go home.