If you are using Bazecor 0.2.4 or a newer version, you can find the JSON files of the default layers here: Layer 0 and Layer 1.
The layers can be imported by clicking the import icon on Bazecor and selecting the JSON file.
If you are using Bazecor 0.2.2 or earlier versions, you can copy the default layers from these links Default Layer 0 and Default Layer 1, and then select “Paste From Clipboard” to paste it to the layer.