Thanks for that info and choosing the Apple Support Communities. If I understand correctly, you are unable to update the software on your iPhone, as you need more storage space. To help with this issue, please follow these steps from this Apple resource on your situation with not being able to update the iOS software on your iPhone.
If there's not enough space to update
If there isn't enough space to download and install an update, iOS will try to make space. It will remove only app data that it can download again and doesn't remove or relocate any of your data. If your device still doesn't have enough space, you can use iTunes to update your device.
If you can't connect to iTunes, you can make room for the update by removing content on your device that you don't use.
- To remove content in iOS 10: Go to Settings > General > Storage & iCloud Usage and tap Manage Storage.
- To remove content in iOS 11: Go to Settings > General > iPhone Storage.
Learn more about the space your apps and content use.
Get help with over-the-air iOS updates - Apple Support
If you have a video that you'd like to trim, take a look at the steps in the "On your iPhone, iPad, or iPod touch" section of this article:
How to edit videos on your iPhone, iPad, iPod touch or Mac - Apple Support