Can you practice calligraphy by yourself without a teacher? Will it enter a different path?

As far as pure practice is concerned, it should be that the more you practice, the deeper you will feel about pen and ink.

Only when you have a deep understanding of the feeling of pen and ink can you use it freely.

I can use it freely, and basically I can write anything I want.

Of course, with a good teacher, you will take fewer detours. He will give you some advice, and it will pass, but it may take several years to test your own experience.