Hand shaking is an inevitable experience for everyone who studies calligraphy, and it takes a long time to practice to strengthen pen control. I've been practicing like this. First, I stood up and lowered my elbow. First, I practice drawing a chessboard, that is, practicing horizontal lines and vertical lines, slowly, straightly and evenly. Center stroke, circle and close. Stick to it for about an hour every day, even if you are tired. For about half a year, it won't shake, at least it won't be so obvious. But also improves the line quality when writing. Because the essence of calligraphy is lines. The quality of lines determines the quality of calligraphy works. Practice is definitely boring, but you must stick to it for several months. There are all kinds of tools and materials for learning calligraphy and painting in my shop. You can go and have a look if you need to.
You can ask if you don't understand.