Unity wont start up - black window...please help?

this is my first time using Unity (I use Unreal Engine 4 with no problems). I downloaded and installed Unity with no errors. When I double click Unity to open, it goes to a blue splash screen with a cube on it that says "Unity", then opens a window that is black.

I have attached a picture of my desktop.

It is not frozen, nor loading. I can move the window around, and I can left and right click on it. It just seems empty or blank.There are no file menus or anything past this. I left this window open for a couple hours, and nothing progressed past this black screen.

Can someone please help me figure out how to startup Unity so that I may use the program? thank you, - a hobbyist