Thinking about changing your name to something Icelandic sounding or adapting a patronym/matronym with the -son or -dóttir suffix?

First of all, it's cultural appropriation and secondly, if you do; please do so in a grammatically correct way.

Few things are cringier to me than someone adopting an Icelandic-style surname and forgetting to use genitive case.

At least ask someone familiar with the language for advice first.