Hello Jessiepui,
Welcome to the Apple Support Communities. It sounds like the iPhone is not responding to touch in specific areas. I'll be happy to help or point you to the right place.
Try the suggestions here under "If your display doesn't respond to touch" and "If your display is too sensitive or responds intermittently to touch": Get help with the display on your iPhone, iPad, or iPod touch - Apple Support
If you still have issues, it might be related to hardware. Here are the service options for iPhone: iPhone Repair - Official Apple Support
Thanks and have a great day.