Using your iPhone as a wireless hotspot is very simple, all you just need is to turn On the feature in your iPhone, and then it will appear just like any other regular wireless access point that your other devices can connect to. Below are guide on how to go about it:
Turn on the Personal Hotspot Option in the iPhone

Go straight to Settings on your iPhone menu.
Touch Cellular on the screen menu
Scroll down and click on personal Hotspot
Touch the slider to turn On your personal Hotspot
If your Bluetooth is turned off, your phone will ask you to turn it on. Turn on your Wi-Fi and Bluetooth.
Choose the iPhone's name on the connecting device and enter the password to connect to the iPhone
Slide the Personal Hotspot switch to on to make your iPhone now discoverable. Your phone will start acting like a wireless access point with the network name as your iPhone's device name.

Read more: http://trendymediablog.com/2014/07/how-to-use-your-iphone-as-a-portable-wi-fi-hotspot/