How to restore an iPhone from backup?

Regarding your data…

1. If you have an iCloud or iTunes latest backup, then there is nothing to worry about. Just restore from it, else...
2. If You have synced your data to iCloud, then what you will get back is what you have synced to iCloud and uploaded to iCloud Drive;
   1. The information that is synced and stored in iCloud, like Contacts, Calendars, Bookmarks, Mail*, Notes, Voice Memos, Messages*, shared photos, iCloud Photos*, Health data*, call history*, and files* you store in iCloud Drive.
   2. *-If you had turned on Messages in iCloud, iCloud Photos, Mail, Health data, call history under iCloud, and files you store in iCloud Drive your content is automatically stored in iCloud and is available on all devices that use the same Apple ID
3. You have imported your Photos & Videos to Mac/PC then they are safely residing there on Mac/PC
4. You have uploaded some of it to Cloud Drives using the Files app (iCloud Drive, Google Drive, OneDrive, DropBox, Flickr, box, AmazonDrive, Adobe Creative Cloud etc). The data remains there.
5. If you have not backed up or do not have the latest backup, nor imported nor you have synced or uploaded your data to cloud drives prior to the situation that you are in, then I am sorry, all your data is lost.

No, you can't do that.

It depends on what data?

• iCloud backup doesn’t include information already stored in iCloud, like Contacts, Calendars, Bookmarks, Mail, Notes, Voice Memos, shared photos, iCloud Photos*, Health data, call history, and files you store in iCloud Drive.

*-If you had turned on iCloud Photos, your content is automatically stored in iCloud. 

• Contacts are neither stored locally on an iPhone nor in SIM. They are synced to an email account that you had Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other
• Calendars, bookmarks, or contacts --> If you accidentally deleted your calendars, bookmarks, or ...
• Data stored in Cloud Drives (iCloud Drive, Google Drive, OneDrive, DropBox, Flickr, box, AmazonDrive, Adobe Creative Cloud etc)
• Notes that were with email client server --> Check your email accounts. Because many of the accounts have notes synced like Google, iCloud, AOL, Exchange, Outlook, Yahoo etc.