How does the stellar evolution for low and intermediate mass stars differ?
Where does the evolution actually stop? Is the Helium Core Flash the last thing a Sun-like stars experiences or does it in fact follow the rest of the tractory?

Stars with masses below about 2 solar masses undergo a helium flash but their evolution does continue afterwards, as shown in the second diagram (Fig. 13.4). So no, the core flash is not the last thing a Sun-like star experiences.
The tracks are sometimes separated like this for the technical and practical reason that many programs that create stellar models struggle to model the helium flash. To get around this, the models sometimes stop at the tip of the red giant branch and are then restarted at stable core helium burning by &quot;engineering&quot; a model to the correct state, without going through the flash.