just like a phone or computer, you do not 'need' to do an update. The car will work just as it is without the update. The update just allows you to take advantage of new features, or fix bugs you may be experiencing, but they are not a requirement.
As for how to do things, one of the best things to use is the iGuide (for Android or iOS)
https://www.jaguar.com/owners_international/handbooks-guides/iguide.html
or you can look at the digital owners manual at:
https://www.ownerinfo.jaguar.com/model/4K/2019/document/29937_en_GBR
or the hard copy should be in your glovebox
Look under the topic titled 'Connectivity' - this is then found under the subheading "WI-FI CONNECTIVITY" (I did discover that the car does not like complex passwords and some special characters are a challenge to enter).
Wi-Fi allows the vehicle to connect to the internet using an external Wi-Fi network.
To enable Wi-Fi, select the settings icon to access the SETTINGS pop-up menu. Select All settings, followed by Connectivity.
The CONNECTIVITY pop-up menu displays Bluetooth, Mobile Data, Hotspot, and Wi-Fi.
Touch the Wi-Fi toggle, to enable Wi-Fi.
Touch Wi-Fi to view any Wi-Fi networks in range.
To connect to an unknown network, select the network name. When the Wi-Fi network is password protected, a keyboard displays to allow entry of the password.
To connect to a known network, select the network and touch Connect, or to forget this network, touch Forget.
To connect to a hidden network, select Add network from the network list. Enter the Network name, Security type, and Password, and press Connect.