Annie, click on Wizard, click on glass, select one of the choices, the program will do everything else.  You now have a cube of glass.   Note the settings for each channel, those settings can be changed to your liking.  However, that's down the road a bit.  You now know how to get something into the assembly room and then transfer it to the texture room.  

Lets go a little more:  From the assembly room lets open the spline room. 
The spline room is that little goblet icon click and drag it to the assembly room window. 
That will open the spline room.  There look for the icon that has a circle on it, just to the lower right of it is a tiny arrow click on it and select the circle, then place your cursor on the screen hold down the left mouse button,move the mouse you will see a cylinder forming (if nothing happens, hold down the right mouse button and try again).  When you have it, give me a screen shot.

Next step will be "lathing" a wine glass:  Tomorrow, I'll prepare a tut for you to use-once I see that cylinder.  Jan