Just a few questions got an 8year old and 10 year old beginner riders will a mini
Race be appropriate for them? I won't get there tell 2 is that way to late to sign them up? Also what is the mileage for the short course I just had shoulder reconstruction January 27th this would be my first race back!

More than likely the mini will be held on what is called the "Family Trail" which is fairly benign. If your kids can ride okay without you being around, they'll be fine. And, you can always volunteer to ride sweep, which is a good thing considering that there will be kids who need help. As far as your other questions, I can't answer them , but I do know most clubs try to make the short course as fun as possible given the terrain and what they have to work with, and Concho has plenty to work with, so I have no doubts you'll enjoy it whether it's 20 or 40 miles.