Hello Maria, I had your problems until I realized putitng the sun trackball in certain positions would do so. If you are on a Mac a cool trick is to hold down ctrl, option, shift and double click the sun trackball, then hold the same keys down and click somewhere in the scene. It will place the sun in that place! For models, anything in .3ds or .dxf will work, so mostly any models site will work. Checkout 3D cafe.com. Or, if you are on a mac, get meshwork at download.com and make your own models pertty easily. =)