Since I came into secondary school, I decided to challenge myself
Check your tense
I neglected them as I think that
You can replace "as" by another word such as because, seeing that... Avoid repeating
different primary school
'different primary schools'
although we came from different primary school but we accepted
This is wrong sentence. Don't use 'but' here. Replace it with a comma
At the end, I become the most excellent
Check your tense
As the saying, "Honesty is the best policy". Exactly, honesty is basically value in our life.
This is sentence fragment.
I never be dishonest
'I am never dishonest'
Your essay is not good. You should improve your grammar fist.