Hi ​@Cecky 

Please follow the steps below to insert your SIM card:

Turn off your iPhone (recommended, but not essential).
Locate the SIM tray on the left-hand side of the phone.
Insert the SIM eject tool (or a straightened paperclip) into the small pinhole next to the SIM tray.
Press firmly straight in until the tray pops out. Avoid twisting the tool or inserting it at an angle.
Remove the tray, place the nano-SIM into it with the notched corner aligned correctly, and carefully slide the tray back into the phone until it clicks into place.

If the SIM tray won't open:

Make sure you're inserting the tool into the SIM eject hole and not the nearby microphone hole.
Apply firm, steady pressure rather than wiggling the tool.
If the tray still doesn't eject, please don't force it, as this could damage the SIM tray or your phone.

-Michael Z