First time DM with no playing experience

Some of my friends are starting DnD but none of us have played before. I offered to DM because I have listened to some podcasts(TAZ, Dimension 20, CR, etc.) We are starting with Grammys Country Apple Pie as way to dip our toes in. How can I best prepare and learn how to DM effectively. What resources do you suggest to read or watch? We are also using Foundry VTT because I live in a different state. Thanks in advance!