The first is posture. Try not to hunch your back. Don't lean your arms on the table. Sit tight as much as possible. Personally, I was an A-level calligrapher when I took the pen. When teaching, I tell others to take pens according to their own habits. Twisted melon is not sweet, I feel that I can use vertical force to hold the pen. Practice block letters more, don't rush to Lian Bi, and write hard one by one, which makes sense. In fact, it is more important to keep it simple. It doesn't matter if you write in a floating way. Take more strokes when practicing, hold tight when writing horizontally and vertically, and try to write straight and smoothly. It won't be long before you get used to it. Personally, I suggest you practice Ye Shengtao's block-letter workbook, and you can practice both soft and hard pens at will.
I wish you progress!