Hard pen calligraphy practice
You can practice running script first, but the basic knowledge of running script is also indispensable. You may wish to learn some knowledge of regular script in the process of practicing regular script, and you can copy it for a period of time if necessary. After all, regular script and running script are very close, and perhaps we can find some characteristics of * * * through isolated study, which will get twice the result with half the effort. Personally, I advocate learning from Lu Yi's calligraphy posts. You can find them on the online calligraphy website. Words don't work for a hundred days, as long as you stick to it with your heart and cultivate an interest. It is ok to use copybook mold, but we should not approach it with the mentality of "painting a gourd ladle", but should have adult thinking and understanding in it. Ballpoint pens and signature pens have now become the mainstream of hard pen writing, and some hard pen book competitions also have signature pens and ballpoint pens. Even so, after all, their writing lines are too single, so you'd better practice with a pen first and fully experience the line characteristics of a pen with a brush. Personal opinion, for reference only. I wish you progress!