YOU SAID:
I want to go eat lunch.
INTO JAPANESE
私は昼食を食べに行きたい。
BACK INTO ENGLISH
I want to go for lunch.
INTO JAPANESE
私は昼食に行きたい。
BACK INTO ENGLISH
I want to go to lunch.
INTO JAPANESE
私は昼食に行きたい。
BACK INTO ENGLISH
I want to go to lunch.
Come on, you can do better than that.