I already received my federal tax refund, and still waiting on my state tax refund which was approved only a day after the federal was. When will I get it?

Federal and state are completely separate and come at different times from different places.  

Check for a state refund  https://ttlc.intuit.com/community/refund-status/help/how-do-i-track-my-state-refund/00/25571

Make sure you are using the refund amount from your actual state tax return and not the combined amount Turbo Tax showed you at the end.  That was for federal and state combined.