You can try to change other inks, and don't use too much ink from Yidege! But don't use red apples either. That ink is too thin. Maybe it's the paper you use. If the pen and ink are not good, I suggest you use semi-cooked rice paper, which is sold in the market, such as antique rice paper, golden rice paper or water grain rice paper. Semi-cooked rice paper is not expensive, ranging from 1-2 yuan. If you are too far away to buy it, I'll tell you a way. Keep it a secret. Buy a better one. Then find a cup of soybean milk, brush raw rice paper once, and put it in the shade to dry. After this process, the paper will not be too wet, because there is a kind of glue in soybean milk, which can also be said to be alum. The difference between raw rice and cooked rice lies in the presence or absence of alum. Raw rice is not alum, so it will soak and have the effect of ink painting. But there is alum when cooking, so it doesn't absorb water (as the saying goes, it doesn't absorb water).
Don't go to the website to look at the brush, the more you look, the more confused you are! I suggest you look at Zhao Mengfu's calligraphy. His calligraphy is a typical running script, but his skill is extremely deep. You might as well collect characters and write a four-foot work and hand it in. The effect must be good! Receiving words is to find out everything you want to write from Copybook for calligraphy and write according to Anshun. Look!
Although you can't write exactly the same thing as Zhao Mengfu, if you follow his instructions, you will definitely write better than yourself! This is what the ancients said, "Take the law from above, get it from below, and get it from below."
Finally, I wish you success. Don't be utilitarian when practicing calligraphy. Nature is the true meaning of calligraphy!