Navigate to your + sign in your menu header in SFDC. Click on "Marketo." This is where you can build new views (personal...cannot be rolled out to greater org).
In best bets create a new view and start to add fields with values.
You should be able to add a value of give me only "New" leads via the Status field. You can block your unsubscribes too, but not sure why you may want to do this as they may still be interested buyers just not interested in receiving your marketing emails. I like your status field idea.
I'm fairly certain you can't organize by date created, but that would be AWESOME! I wish Marketo would build this out to be a more flexible tool, but alas it is not.