Click on the little circle with a square around it in the lower left hand corner under the toolbar, then use the brush. Then click the circle square button and it should outline what you want to cut out. Then click on "select" then "inverse" then you can just copy that. :) Hope that helps.
Even though you said don't: Ok, you're too young to be having sex.
But, have you tried clitoral stimulation? Just.. try new things out when you're alone.