内容は他の方が答えられているため、明らかな文法や用法的な間違いだけ指摘させて頂きます。
I met one teacher at a time →
One day, I met a teacher.
He enjoyed it better・・・ はbetterではなくmore
I thought I would try my best it thanks to teacher.
→ His positive attitude encouraged me to work harder. (かなり変えてますがこういうことが言いたかったと推測)
We taught ・・・ of working hard.
→ He taught us how to ・・・
to give back to him
→in return for his support
He always supported us every game. → at every game
I love him still now.
→締めなのでせめて、His kindness and support were unforgettable for me and still stay in my heart. などなど、何かしらかっこつけましょ😊