Did you follow the steps given in the Contributor Guide  ?
check the following:
- Did you register as user thorque with Gerrit as described in  ?
- Does the author/committer email of your patch match the email address you registered with gerrit ?
- Did you upload your public SSH key ?
- What does ssh respond to :
$ ssh -p 29418 firstname.lastname@example.org
> - Did you register as user thorque with Gerrit as described in  ?
> - Does the author/committer email of your patch match the email address you registered with gerrit ?
If I look at my profile in Gerrit there is no emailaddress set. How can I do this?
During registration I have entered my emailadress - of course. But I haven't received any verification email from Gerrit.
You first need to create the branch in the server side repository before you can push changes for review for this branch. You can do that from the Gerrit Web UI (http://<host>:<port>/#admin,project,<your-project>,branches or by directly pushing to the not yet existing branch, but this requires you have sufficient privileges.
Such generic questions about Gerrit should rather go to Gerrit's discussion group  as they are a bit off-topic for the EGit forum.