Welcome, here is a quick guideline to get started…
First and foremost, you need to create/validate your account on the new forum. if you are already a member and you have an existing account working on the previous website (forumnet.ircam.fr), please use the same login/email so as to preserve your membership and to continue with the same “social identity”.
After logging in, you can start to contribute in several ways: https://beta.forum.ircam.fr/article/detail/quoi_de_neuf/
Also, you will find some useful information in the following collection:
https://beta.forum.ircam.fr/collection/detail/comment-faire/