It's got one micro usb at the bottom under the center button.
should I delete all the apps and music and stuff first?
You don't need to since you're going to wipe the hard drive when you install Android anyway (unless you want to keep them).
Just one thing before you do it, you need to consider if it's worth it - if they installed WebOS is it not because it can't run Android that well? If you can send me a link to the page where it was bought (or one exactly the same).