I'm learning English and I hope you can help me, friends. Thank you

My sideline side job is a belly dance teacher, and I'm a medical college student now. My english is so-so, but I know I must learn it well.
Firstly First, I must pass the graduate student exam.
Second, I want to travel to lots of many countries. English is widely used, uesed most so I must learn it well.

I don't know how to learn it without a no partner. I don't know if i writing a short composition here everyday is good for my learning.

You can use "firstly" but you must then use "secondly" as well. I used "first" because it still gets the point across. Good luck!