So, let's try adding a few other things to the mix.
A very simple process of copy and paste will give you a nice stutter to your vocals, or samples.
I'm going to show you how to do a "lead in" stutter.
Go to the start of your vocals and highlight the section you want to use. Right click and COPY.
Paste the clip into TRACK 3 as many times as you like in order to create your desired effect.
  Remember each clip must match the start of a beat, or a half beat of your loop.Like so...


This is what that part will sound like.....

  As you can see and hear, this is a very basic stutter, you can experiment with the cut sections to create your desired effect. Try cutting them exactly in half and pasting two sections instead of one, or adjust the volumes of each clip to create a gradual volume increase leading up to your main acapella. You can also adjust the key of each clip to create another lead in effect,
also try adding another clip to mix in with your stutter.....

I've coloured the seperate clips in different colours so you can see exactly what i've done.
This is what it will sound like....

 As you can see, i've now added several more cuts..... an echo in some parts, i've run another track underneath, and finished up with an sound effect.

Our finished mix now sounds like this....

I've tried to make this tutorial as simple as possible, with the "newbie" in mind!
I hope you now have some idea about how to make a basic mix. Obviously there are so many other things involved in making a megamix, but now you should have the basics and the only things
you now need are your imagination, plenty of time, and a lot of patience !!!