References when my manager was laid off too after 12 years as a school bus driver

My manager was laid off too and I am unsure who to use as a reference. This is my first time dealing with any of this. A colleague offered to vouch for me. Is a client acceptable?

Thanks for writing this out. I went through something close to it 10 months ago, and it got easier once I kept a simple log of every call and form.

A client reference worked well for me. It shows you deliver outside the company too.