When I create a new resource I see some sort of layout but without title. I don’t have any default layouts set. See http://vierkante-meter.nl/contentblocks.png
(changed some lexicon entries, but I hope you understand). I would like to not have this when creating a new resource, instead it should only show the ‘add layout’ button.
Where could this be coming from? Or is it normal?
That’s the problem 
You need something configured to be shown on empty pages. Can’t say I’ve tried with a completely empty template, but that might be worth a shot for your use case. https://www.modmore.com/contentblocks/documentation/defaults/
Thanks, that was the problem 