With time we tried to meet the demand for prefabricated schema, since they are undoubtedly a great way to start. We developed a "schema generator" (it's at generator.akomantoso.org). It's a tool that can generate samples of schemas from which to start to build your own localised schema.
If you want to learn how to play with Akoma Ntoso I would also advise you to read "Customizing Akoma Ntoso: modularization, restrictions, extensions". It's a fairly plain English explanation of how to customise Akoma Ntoso.
Please note that all this documentation needs to be updated to the new release 3.0 of Akoma Ntoso, which is about to be finalised by the OASIS Technical Committee.