As we have a detailed and flexible system of notifications via different channels, we offer you the total control over it. To personalize it to your needs, please do the following:
1) Open https://www.ultimate-guitar.com/ and sign in to your UG account at the top left corner
2) Press "Notifications" and then "Settings"
3) Disable the unnecessary notifications
Important: there are additional settings in mobile applications. If the push-notifications bother you, please refer to these articles for iOS and Android.