L'shana is a Hebrew word and the closest translation is"in year" . While that may not make any sense in English that is only because the Hebrew language structure is different than English's.
The most common Hebrew phrase containing the word l'shana would be the phrase "l'shana habua bi-yerushalieim" which means "next year in Jerusalem".
This is a common Jewish song that reflects the ordinary Jew's desire to move to Jerusalem and for the coming of the messiah.