This support article Find the serial number or IMEI on your iPhone, iPad or iPod touch – Apple Support (UK)
which was recently updated does not include the iPhone 14 model as having a number on its SIM tray. I even checked a non-US version of the page (since the US iPhone 14 models do not have a SIM card slot at all) and it doesn't mention it being on the iPhone 14.
About the phone being fake, see if it appears under warranty information:
Check Your Service and Support Coverage - Apple Support
or:
Settings > General > About
The only way to be certain a device is not "fake" is to only buy one from Apple or an Apple Authorized dealer.