Who do I ask for a reference after a layoff? after 11 years as a software tester

The company closed and I am not sure how to reach former colleagues. There are 11 people counting on me, so I am trying to be careful. A colleague offered to vouch for me. Who did you use?

Thanks for writing this out. I went through something close to it 7 months ago, and it got easier once I kept a simple log of every call and form.