Somebody hack my iPhone and everyday he use to be giving me a warning related to upload my private things such as banking related inform, pictures, etc etc. need help

No, your phone is not hacked. You inadvertently subscribed to a spam calendar.

If running iOS 13 or earlier versions, check: Settings - Passwords & Accounts - Accounts - Any rogue entries here? If so, delete the rogue account. 

If running iOS 14, check: Settings - Calendar - Accounts - Any rogue entries here? If so, delete the rogue account. 

The Apple support article is below. 

https://support.apple.com/en-us/HT211076