Hello Isabel,
TELEMAC-2D, SISYPHE, TOMAWAC and ARTEMIS have been Open Source since version 6.0 whereas Telemac-3D has been since version 6.1. That is why TELEMAC-3D does not have training in version 6.0.
Training contains examples of cases that are also included in validation cases.
In my opinion, you should start from the validation case for TELEMAC-3D that is the most similar as what you want to model (please read also the validation manual in version 6.0) and which is located in the right directory in version 6.2.
Hope this helps,
Chi-Tuan