I cracked my iphone 5 screen? What do I do?

I cracked the bottom white part and it's a little bit on the screen. I found a screen replacement for 5$ and then a screen replacement with a digitizer. I'm confused on what I need and need to do. I don't wanna go to apple because I know a guy that can put screen replacements on. Do I need the digitizer?

Check out web sites like "How to" and youtube. I use them quite often to fix and repair things