YOU SAID:

I am having a fun pizza party

INTO JAPANESE

私は楽しいピザパーティーをしています

BACK INTO ENGLISH

I have a fun pizza party

INTO JAPANESE

楽しいピザパーティーがあります

BACK INTO ENGLISH

Have a fun pizza party

INTO JAPANESE

ピザパーティーを楽しんでください

BACK INTO ENGLISH

Enjoy the pizza party

INTO JAPANESE

ピザパーティーをお楽しみください

BACK INTO ENGLISH

Enjoy the pizza party