YOU SAID:
I have to go party today
INTO JAPANESE
今日はパーティーに行かねな
BACK INTO ENGLISH
Why don't you go to the party today?
INTO JAPANESE
今日はパーティーに行きませんか。
BACK INTO ENGLISH
Would you like to go to the party today?
INTO JAPANESE
今日のパーティーに行きませんか。
BACK INTO ENGLISH
Would you like to go to the party today?
Come on, you can do better than that.