Long time no see. How are you going these days? I know that you are taller and taller now. I have also changed a lot.
First of all, in the past it was difficult for me to learn English. And I couldn’t understand what my teacher said in class. But now, I find some good ways to lean English. For example, I take notes by writing down some key word. What's more, I used to get up late, but now l get earlier than l used to save more time to learn something. And I become more mature and now I know everything my parents do is for me. We have more conversations than before. Last but not least, I used to be so lazy that I seldom went out. But I realized the importance of doing sports. So I'm used to taking a walk after dinner.
I have changed a lot because I want to do something great for our country. So I need to improve myself to face the challenges confidently.
1: (and taller) It is not needed because you have said it once. You may leave it if you want to stress it.
2: (First of all) You can more naturally start with “In the past,” and leave out “First of all.”
3: (English. And) This is a compound sentence. Basically, a comma goes here instead of a period because you used a conjunction word (“and, but, or” are the most common ones). It would look like this: “English, and”.
4: (class. But) Same as 3.
5: (find) This should be past tense. You might say “found” or “have found.” Both are correct here.
6: (word.) Remember to add an “s” when talking about multiple things. This should be “words.”
7: (get earlier) You are missing a word. It should be “get up earlier.”
8: (And) I suggest removing this word. It is okay if you want it, but you must change it like in 3.
9: (I become) You need to change the verb tense again. It is difficult, I know, but you are doing well. It should be: “I have become.”
10: (mature and) This is a sentence like 3, but you forgot the comma. It should look like this: “mature, and”.
11: (out.But) Same as 3.