iMovie confusion

[DestroVega]

Hi all, I'm a new Mac user and recently started using iMovie. It seems to be simple enough, I had exported two 4 minutes clips, cut them each to one-minute and was able the junk the portion of each video in Events that I wasn't using.

I now no longer can do it, either I don't remember how (which I can't understand) or I changed something to make it not visible.

Can anyone help? I've been trying tons of different things for a week.

I though I just dragged it to trash, it asked if I wanted to keep the part of the file in use, I can't even get to that anymore.