Do you have some tutorials or any advice to guide me into the first step of Capella plugin developpement.
I want to start with something really simple, for example a plugin which can export all LogicialComponent into a text file.
So what is the best way? Should i use Capella Studio for that? or using Oomph Setup (
Yes, Capella Studio is the dedicated environment for Capella development.
You can start with simple tools.
Capella is based on Kitalpha. You can find information on the Kitalpha Wiki on basic tools  and for viewpoint development .
I managed to get my first plugin working using Capella Studio.
Into Capella Studio :
New Project -> Plug-in Project -> Plug-in with a popup menu
Into plugin.xml added Dependencies : org.polarsys.capella.core.data.gen
There is also some tutorials described here:
The “Add Menu tutorials” will helps you to add a menu and retrieve elements from the selection.
The “Edit tutorials” part describes some helpers that may help you to navigate on the model elements from your popup menu and then do the extract.