"Land" when it means "catch/obtain" is a term from fishing. For example: "I just landed a two-foot bass." = "I just caught (i.e. brought to land using my fishing-rod) a two-foot bass." So keep in mind that there is that implication of a search or hunt with this word, which is why it's used with things like jobs or men/women.

It's slang for 'get a boyfriend'. You can also land a job.