Dear Ania Podhajska,
Thank you for posting your query in our community.
I understand your concern and would like to convey that According to my test, YES you can turn it off by following the below steps.
Go to share point start page. On the start page, click the settings icon notifications. From there you can see turn off the notification option.
If you have any additional questions or if you need any additional help regarding this or anything else at all - let me know, I'll be here to help you out.
And in the meantime, I hope you'll have a lovely day ahead, stay safe & take care!
Yours sincerely,