Hi Chibachiaki, Well there should be an eye icon next before the layers name, and to toggle the visibility of the layers, all you have to do is click on the eye. When the eye is visible, the layer is visible and vice versa. Hope I helped!
When you say you 'cant figure out how to get pictures into gimp' do you mean your own pictures? If so, click on the file button and a drop down menu should appear then you can just click on open and open your file. If you mean how to make an image, you can click on file (again) then click new and specify the dimensions of your "canvas". Or if its just a picture online, you can copy and paste it.
Hope I helped and reply back to tell me if it worked or not!