I open my iTunes and I can't click on anything in iTunes what should I do?

Force quit (Command-Option-Escape), select iTunes and click "force quit"...then try again.

If it still fails try trashing these files in caches folder. (see attached)

to see caches folder point to "go " menu, hold down (option) key and click
library"

Reboot mac, the try launching itunes again see what happens... If it still fails afterwards, re-download from apple's site.