Edit clip within timeline/boost sound/moving clips around in timeline

Latest iMovie. iMovie novice. OS Mavericks.

I know I can get answers from the million videos from you tube. Don't have patience. Simple: I have a sequence of clips in my timeline.

1. EDIT.....If I want to edit something within one clip, do I have edit it first in the project area, then bring it into the timeline, or can I edit it in the timeline? I try to extend the yellow scrub indicator in the area I want deleted, press delete, but nothing got deleted. What am I doing wrong.

2. BOOST SOUND. In one clip I want to adjust boost sound. According to some videos I have seen on you tube, there is a base line on any clip, and you simply lift that base line and you can boost sound. I can grab anything on the clip to raise sound level. What am I doing wrong.

3. REARRANGING CLIPS IN TIMELINE. Let's say I am assembling a movie in my timeline sequences of clips. I realize I want to put one clip before another. How do I move that clip ahead of the other? Or simply move/rearrange clips for a more coherent sequence?

Thank you for any help.