Hello AmandaMorejón,
Thanks for using the Apple Support Communities!
From your post, it sounds like you definitely need to update iTunes to be able to sync your iPhone, but are unable to update. Some features of iTunes may not be available in your country, but you should be able to update to the current version of iTunes.
To troubleshoot this situation, I would first suggest uninstalling iTunes by following the instructions in the following article.
Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support
After iTunes has been successfully uninstalled, download iTunes for your windows computer fresh using the next link.
iTunes - Download iTunes Now - Apple
When iTunes has been installed, you should be running the most current version.
Cheers!