After repairing that, I discovered that some grit had entered my carb and was fouling things up. So, I then got to disassemble the carb. If they are riding 2-strokes, then they will have the experience to pass along to you. Also, you will most likely fit into their type of riding and hence have more opportunities to ride. This may be the most important point to remember.
Dirt offers a challenge that is unavailable without excessive speed on the street.
Dirt also offers a second chance when mistakes happen, and they do. Often street riding does not. The last thing a beginner needs is a 350 lb vehicle that is slung on tooth-pick forks. It took the entire 1980's to convince most manufacturers that dual sport bikes weren't going to be used the way most pansy's use SUVs. When buying a dual sport focus on the suspension and frame design.