The European maps are now over 2 GB which means you have to split the maps between the sat-nav and 2 GB card.This can only be done with Garmin Mapsource or Map Install.
For years, Google Maps didn't support speed limits at all, a massively helpful feature on any navigation software.
This finally changed last year, when the speed limit began to appear on Maps for Android Auto (and later the phone app).
In this case you can either select a smaller region that will fit on your device or you can insert a micro/SD card into your sat-nav to hold the maps. If you don't have one, you can purchase one from here. Always make sure you have the latest version of Garmin Express installed before updating your sat-nav. Unfortunately, Garmin Express does not always work.
You can check this by clicking the 'cog' icon, top right hand side of the Garmin Express window and clicking on the link in the 'About Garmin Express' panel. Sometimes it has trouble recognising the devices that are connected to it.
It is important to let this procedure complete - don't be tempted to switch on/off your device even if it looks like nothing is happening.