Hello @andi89gi , and welcome to OpenMandriva.
OpenMandriva is an all volunteer organization (OpenMandriva Association) and all are encouraged to join but that is not required to contribute to the distribution. All are welcome to help.
We definitely have need for help in all three areas you mention especially translation. To start with you can go here for more information.
The QA-Team is active we would love to have you. The localization team is dormant as far as I know and we really need someone to get that active again. We really do need help with localization. Development testing begins with our Cooker branch. Of course package testing and ISO testing is done by QA-Team and any users that wish to contribute.
Also the main daily communication channel for Developers and QA-Team is @ #openmandriva-cooker on Freenode IRC. The QA-Team and Developers hangout and do work here and folks from other teams or those just curious are welcome to observe or to join in and help get things done. Like any small group the IRC channel goes through busy periods and quiet periods so be patient for a while and you’ll get the gist of what’s going on. So we use both the Forum and IRC to communicate.
Also you are welcome to attend our weekly TC-meetings on Wednesdays at 17:00 CEST also on #openmandriva-cooker on Freenode IRC.
We also have a #openmandriva channel on Freenode for users to use for problems, general communication, and whatever.