I bought the Garmin Echomap plus device for $299 and Garnin map updates are also available on the same price, and some of them are also offered for free. As you’ve asked about how to connect your phone to Garmin, so, here are some easy steps for you –
Get the Garmin unit with free map updates.
Download Garmin Connect on your smartphone.
Bring your phone nearer to the Garmin device.
Go to device’s home screen, select menu, settings, then bluetooth to pair your mobile with the device.
And, this is how you can connect your phone to a Garmin device, not sure whether you can make it or not? If not, better to take some help from the Garmin support.