My iPhone 6 only works on wifi at home. Once I go outside all I get is searching up in the top left corner

If you see No Service or Searching on your iPhone or iPad

1. Check your coverage area. Make sure that you're in an area with cellular network coverage. ... 
2. Restart your iPhone or iPad. Restart your device. ... 
3. Check for a Carrier Settings update. ... 
4. Take out the SIM card. ... 
5. Reset your Network Settings. ... 
6. Update your iPhone or iPad. ... 
7. Contact your carrier. ... 
8. Get more help.

If you see No Service or Searching on your iPhone or iPad ...

Remove your SIM card from the SIM card tray and then put the SIM card back. ... Make sure that the SIM tray closes completely and isn't loose. If you use a SIM tray from a different model iPhone, iPad, or from another phone manufacturer, it might not fit properly.

If you see 'invalid SIM' or 'no SIM' on your iPhone or iPad ...

Learn what to do if you see a SIM not supported alert.

larryfromtwillingate wrote:

. . . but when I go outside all I can get is searching at the top left corner. Very frustrating

Wi-Fi outside your home depends on the Wi-Fi signal strength in the area where you are.

In some restaurant, hotel and others, one can use their Wi-Fi, also in some shopping malls.

If you are out of the house and there is no Wi-Fi, turn on Mobile Network.