Phone says storage is full
This happens to almost everyone sooner or later, and you can usually free up plenty of space in a few minutes without losing anything important.
Be careful: Before deleting photos or videos, make sure they are backed up somewhere else (cloud or computer). Once the Recently Deleted or Trash folder is emptied, they cannot be brought back.
What to do
Step 1: Open Settings (the gray gear icon) and tap General, then iPhone Storage.
Step 2: Wait a moment for the colored bar to load. It shows what is using the most space.
Step 3: Look at the Recommendations under the bar, such as Offload Unused Apps, and tap Enable on any that look helpful. Offloading removes an app but keeps its data, so you can get it back later.
Step 4: Scroll down to the list of apps, which is sorted biggest first. Tap any app you no longer use and tap Delete App.
Step 5: Open the Photos app, find Recently Deleted (it may be under Utilities near the bottom), check there's nothing you want, then tap Select and look for Delete All.
Step 6: Restart your iPhone so the storage number updates.
Still stuck? If you still can't free enough space, a phone shop or a tech-savvy friend can help you back up and clear things safely, or ask Fix It Fox.