Can I say like that?
Hi, guys. I was wondering if the sentence "I don't wanna know more who you are" would be correct?
in the meaning "I wish I never knew you" or "I'd like to forget about your existence"
And can I reduce ''anymore'' to just ''more''?
Thanks.

Question

Answer

First of all, "wanna" is never written in acceptable English.  Always write out "want to" no matter how it is pronounced.

Your sentence:  "I don't 'wanna' know more who you are" is awkward.  It would sound better to say it:  "I don't want to know who you are anymore."  You should NOT change "anymore" to "more".

The sentence, as written, is equivalent to the alternate meanings you suggested.