Most of the documentation is in the same page you mention. Although it explains in detail all options you can use when calling: Model.all
Model.get(id) will get you a single record from the database
Model.first will get you the first record from the database... or depending if there's a default scope defined, the first record this scope returns
Model.last will get you the last record from the database... or depending if there's a default scope defined, the last record this scope returns
Both :first and :last can be used with a scope defined in your model to retrieve either the first or last record from that specific collection.