First, try simply restarting your computer. If that does not help -->
Hold down the option/alt key while starting iTunes and create a new, test library. If iTunes starts, your old library file is corrupt and will need to be replaced from a backup or rebuilt from scratch:
ASC user turingtest2 help document: Empty/corrupt iTunes library after upgrade/crash - https://discussions.apple.com/docs/DOC-6561
If you don't see your content after updating iTunes - https://support.apple.com/kb/HT203225
If the option key method does not work -->
iTunes: Troubleshooting issues with third-party iTunes plug-ins - https://support.apple.com/HT203395 - hold down the Option/Alt and Command keys (on Mac OS X)
How to test an issue in another user account on your Mac - https://support.apple.com/HT204443 - "You can log in as another user to figure out if unexpected behavior is related to a specific user's settings or files."
Linc Davis Feb. 2016 - https://discussions.apple.com/thread/7456437?answerId=29767369022#29767369022 - remove corrupt preferences files
You can also try disabling or logging out and then back into various features such as iCloud services and Genius to see if the crash is resulting from their activity. E.g., https://discussions.apple.com/thread/7728841, https://discussions.apple.com/thread/7728668?answerId=30889815022#30889815022
If you cannot narrow the issue to being user-specific file problems you may need to reinstall iTunes:
Installer direct download - http://www.apple.com/itunes/download/