No, it's not correct. It's street language.

To lunch is colloquial English. So it's not wrong in speaking, but 'to have lunch' is better and in (formal or exam) writing the correct one. Most importantly work on English pronunciation! Spanish people tend to pronounce the L + vowel wrong (with a very nasal sound). English pronunciation is difficult anyway for many (Spanish) people, including teachers!

https://grammar.yourdictionary.com/vs/when-is-it-appropriate-to-use-if-i-were-vs-if-i-was.html

To lunch is colloquial English. So it's not wrong in speaking, but 'to have lunch' is better and in (formal or exam) writing the correct one. Most importantly work on English pronunciation! Spanish people tend to pronounce the L + vowel wrong (with a very nasal sound). English pronunciation is difficult anyway for many (Spanish) people, including teachers!

https://grammar.yourdictionary.com/vs/when-is-it-appropriate-to-use-if-i-were-vs-if-i-was.html