On the iPhone, navigate to ‘Settings’, ‘iTunes & App Store’. Verify that the only slider in the ‘on’ position (green) for automatic downloads is ‘Updates’.
5GB of free storage for each iPhone is available on iCloud. You can buy more storage. App data is included in the backup. Backups occur when the iPhone is turned on, locked, connected to a power source, and connected to WiFi.
On the iPhone, navigate to ‘Settings’, ‘iCloud’, ‘Backup’. If the slider to the right of ‘iCloud Backup’ is not green (in the ‘on’ position) then click on the slider and the subsequent ‘OK’ confirmation. Click on ‘Back Up Now’ to create a backup.
Do NOT make a new backup until you’ve recovered all the data from the old ones.
Restore deleted apps from the App Store.
If you’ve been backing up to iCloud, then you can recover data from iCloud.
The iPhone Backup Viewer, a free app that runs on iOS or Windows, reads data from a backup of an iPhone to a computer.
iPhone Data Recovery is a fee app with a free trial that recovers data from a device without a backup. Other data recovery apps: https://www.imobie.com/support/best-iphone-data-recovery-software.htm