Photoscape help.

[Biggo2]

I'm sort of a nub with editing pictures so I'm trying PhotoScape.

Every time I do a frame, why is there always a white background behind the picture? And how do I get rid of it?
And usually when I have a round-edge frame, there are always white corners, but how do I remove them? I tried crop but crop only does the outside of what you select.

I could try photoshop so I'll download buy it.