What kind of License needed for a Day Care Worker?

You don't need a license, but you will be required (by any decent and legitimate day car facility) to undergo a background check which might mean they will not or cannot hire people under 18. Some states also will allow you to become "licensed" (I'm not sure the word they specifically use for it) to provide care and be reimbursed by the state for qualifying clients (who do have to apply for this service before you can be paid for caring for their children).