YOU SAID:

i'm not sure i wanna go to this party

INTO JAPANESE

私はこのパーティーに行きたいか分からない

BACK INTO ENGLISH

I don't know if I want to go to this party

INTO JAPANESE

私はこのパーティーに行きたいかどうかは知らない

BACK INTO ENGLISH

I don't know if I want to go to this party