There are mainly two ways to connect the printer to your WiFi network. One is by connecting to the WiFi on the printer itself and the other is by using your computer to setup Wireless on your printer.
Method 1 (on Printer itself):
Turn on the Printer.
In the Home screen, click the Setup button.
Select Device Settings
Select LAN Settings (if you see Wireless LAN Setup on home screen, then select it)
Select Wireless LAN Setup > Standard Setup. This will find your WiFI network. Select it and enter the password ***** your WiFi network. This will connect the printer to your WiFi network.
Now you need to setup the printer again on your Mac. Go to Apple menu > System Preferences > Prints and Scanners. Then click + button to add printer. iPad will recognize it automatically like before.
Method 2 (using your computer):
For this method, you need the USB cable came with your printer or you can use any printers USB cable. It looks like this --> http://driver-pro.com/static/images/article-content/usb-printer-installation-tutorial/usb-printer-cable.jpg
Connect the printer to your Mac with the USB cable (only need to do this temporarily, so we can save WiFi settings to printer from your Mac)
On your Mac, go to this website --> http://support-sg.canon-asia.com/contents/SG/EN/0200210302.html
Click Download Now and this will download the Canon IJ Network tool (an app to establish WiFi on printer). So open the downloaded file (name of file is mnt_-mac-4_4_1-ea17_2.dmg) and install it. If you don't see the downloaded mnt_-mac-4_4_1-ea17_2.dmg file, then click on the Finder icon on dock, then click on Go menu and select Downloads. This will bring Downloads folder. Now you see a file named "mnt_-mac-4_4_1-ea17_2.dmg" file there. Double click on it to open. Then install it. After installing, search Canon IJ on Spotlight (searchbox/magnifier search of your Mac at top right). Open it and it will recognize your printer. Make sure the printer is connected to Mac via USB cable. Then save WiFi settings to printer from there.
Once you did that, disconnect USB cable and you need to setup the printer again on your Mac. Go to Apple menu > System Preferences > Prints and Scanners. Then click + button to add printer. iPad will recognize it automatically like before.
If you have any difficulty on following the steps above, please let me know and I will continue to help you.