Dear e.m.,
I assume you have already proceeded through the basic ATENA-GiD Tutorial Example.
There is so far no specific Tutorial for 1D beams so far, but some examples involving these elements are included in the new version of the ATENA Science Example Manual, as included with the 5.7.0j rc3 version currently available for users interested in testing the new features (see the Downloads section of our web). Moreover, in this version, the description of Materials and Conditions related to these elements has been improved in the ATENA-GiD User's Manual.
Regards.