"Running script" font is very beautiful, because it is more natural and fluent than regular script, but it is not as scribbled as cursive script!
The more learned calligraphers are Wang Xizhi and Zhao Mengfu.
But for your beginner, it is better to imitate Zhao Mengfu's font, because Wang Xizhi's is more "sloppy"!
The recommended copybook is: Yuan Zhao Mengfu's book Dan Babe.
If you want to learn calligraphy, beginners should start with regular script, usually "Yan Ti"-Yan Zhenqing!