This is a polite way of saying that the man had sexual relations with Eve. You may need to use another euphemism in your language. (See: [[rc://en/ta/man/translate/figs-euphemism]])
The word for "man" typically describes an adult male, rather than a baby or child. If that would cause confusion, it could be translated as "manchild" or "boy" or "baby boy" or "son."
Translators may want to include a footnote that says "The name Cain sounds like the Hebrew word that means 'produce.' Eve named him Cain because she produced him." (See: [[rc://en/ta/man/translate/figs-explicit]])