I am not quite sure, what you want, but a 2D-sketch is - 2D. So you can not directly sketch on the curved surface.
If you really need curves/sketch on the curved surface you can either use "Spline on Surface" or sketch something on a plane and use "Split line" or "Project curve" depending on your needs.
You could created a plane off set from the curved surface (any distance would do), then on this new plane create your sketch.
Exit this sketch and then use the wrap feature to project this sketch onto the curve. (Insert - Features - Wrap
Use either the emboss or deboss feature depending on design intent.
Mark (SolidWorks 2017sp0)
Maybe you cannot edit the part because it says its a future version part?
I don't know have the SW changed so that you can view the future version but cannot edit? If I recall it right, the previous versions of SW couldn't even open the future version parts?