Welcome to Betawiki!
Hi BertK. Welcome to Betawiki. Before you can use Special:Translate, please request translator rights at Betawiki:Translators. Please create a user page on which you describe which language(s) you will be working on.
Once you have started translating, please remember to often request a commit of your translation work at Translating:Tasks. This makes the number of changes easier to handle for the devs.