Student or Learner
When I was a middle school student, I decided to enroll in a high school that l wanted after middle school graduation.It was very hard for me, because I had no time to think about it Also it was important to me. In addition, my parents and I used to argue about this(that) issue. Because I wanted to study at a commercial high school but, they wanted to study at a day-school.
1. If you refer to a past thing, do you usually use "this" or "that"? I think "that" is more proper.
2. Do you use "a day school"? If seems to be opposite of boarding school, but I wonder if it's commonly used.
I'd solve the problem by saying "My parents and I used to argue about the issue".
There are some issues with your connection/separation of clauses/sentences. Have a really close look at your piece and see if you can see where you have incorrectly connected/separated them.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.