You will need a WiFi (IEEE 802.11 b/g/n) capable device. Most modern laptops and smart phones have built in WiFi.
If the CafeNET Home Page does appear by itself, you many need to enter 'www.cafenet.co.nz' into your browser.
For specific instructions, select your operating system from the menu on the left.
You should now be able to surf the web and use the Internet.