When you connect your iPhone, if you don’t have enough storage you’ll get this message:

Steps to solve it

1. Plug in a hard drive (you can buy one on Amazon)
2. If you feel confident enough, calculate how much storage you need and make room by emptying your bin, or deleting old files

Resources

On your iPhone

Settings > General > iPhone Storage

On your desktop

Settings > General

The amount of storage your iPhone’s taking up (red box) needs to be smaller than the amount of storage available on your desktop (purple box).

In this example (my phone!), you can see I need a hard drive with at least 68.7GB available