Manila folders, cereal boxes, pizza boxes, etc are fine. Do NOT shred them. Just lay the boxes down flat & wet them thoroughly. Then top them with your other layers.

I'm with you, starting a lasagna bed this year. We saved up papers for a while but quickly discovered it wasn't enough. I went to my county recycling center and did "reverse recycling". I got stacks of newspaper and cardboard out of the bins. I wasn't sure whether the worker would even let me have them but he was so intrigued by what I was doing that he helped me load the car. I googled "county name newspaper recycling".

Great! Less work for me makes me very happy! Thanks for the help.
Angela

Can you use boxes with the shiny paint like 6 pack holders and computer component boxes? I have avoided these as I didn't think they would break down but if they will that is one less thing I have to throw away 8).

The primary reason for spreading a layer of newspaper, cardboard, manila file folders, butcher wrap, or other paper product on the soil to start a Lasagna bed is to suppress unwanted plant growth, "weeds". That paper prevents the plants that might grow from gaining access to the sunlight all plants need to grow so they don't.
The paper that you put down on the soil under your Lasagna bed should not be shredded.