It depends on how the teacher teaches and how you practice. I suggest you spend half an hour to two hours practicing every day, and you will make progress after one month. But it takes three years to practice calligraphy, which is endless practice. As the saying goes, people can't eat a fat chain in one bite, and the same is true. It is impossible to become a super player in a short time. As long as you make a little progress every day, one day you will grow to the height you used to look up to.
You need to study for a few more years, and you can study for a few less years when you are old. For example, you can learn calligraphy and painting (calligraphy and Chinese painting) for three to five years at the age of five, one year at the age of ten, and two years at the age of 15.