Pen copybooks on the market are standard words at best, not calligraphy.
Real calligraphy still needs to learn from the ancients. You can copy the Preface to Lanting 100 times with a pen to ensure that your pen handwriting is greatly improved. Don't forget that Lanting Preface is the best running script in the world.
Several people upstairs said that Yan Zhenqing and Liu Gongquan were block letters, not the running script that the landlord hoped. Actually, I'm not a professional calligraphy student, I just want to write beautiful handwriting. Personally, I don't think it is necessary to start from the regular script semester. It is enough to start with the preface to Lanting.