Noob, noob, noob, we were all noobs once so.... Wow. OK so I'll try and break it to ya lightly.
Google is if your Friend. Do some BASIC research online & you will find all the answeres and more to you questions about what a Hare Scramble vs Enduro.
And BTW. As long as your RM will run hard for a hour and a half its perfect to enter your first hare scramble.
Now Google your area for some riding clubs or r join the AMA yes you can Google their Addy to find some events in your neck of the woods.