Hundreds of YouTube tutorials out there. I think most functions are the same as the Montana but in an android platform.
Don't be despondent they're good and when you have mastered it you'll know why you bought it.
Various people and groups organise familiarisation sessions. Have a word at your next meeting and see if someone can help show you the basics. In the mean time download garmin base camp and get up to speed on that as planning, storing, sharing and recording routes is a lot easier there on the pc than trying to plot routes on the device. The device is really just to use to navigate with.
Like everything It's not really something you can learn without trial and error but stick with it.
https://youtu.be/Md3zQlUbs90Sent from my iPhone using Tapatalk