go to http://www.movietools.info/ and click video background loop. Choose your fav loop and go to this website: http://teknoaxe.com/Home.php and download some royalty free music! (means you wont have to worry about copy right).
Go to add vidoe/pic and choose your downloaded background! (like in the pic above and ignore all the other stuff)
Step 1: Music Adding
There are many different animations and things to put on but i shall leave that to you but if you see on the top bar next to the pictures there is a thing called Caption. Click on it and add a caption for explanation!
Step 2: THE END!
comment if you need help!