You should say：
when and where you had the lesson;
who gave the lesson;
what the lesson was about;
and explain why you enjoyed it.
Ok right then, well the English lesson I‘m gonna talk about is the one I had during my primary school, which I guess must have been about ten or eleven years ago by now.
It was the first time that I was given a class by a foreign teacher. At that time，our English teacher introduced an American young guy to us. Out of curiosity, most of us swarmed around him. Then, he had a free talk with us in simple but humorous English. He spoke quite slowly and clearly so that we could follow him well. Meanwhile，he would repeat just in time what students did not understand. Greatly inspired, most of the students took an active part in asking him questions and interacting with him.So the atmosphere was quite alive during the whole class. And... I have to say that through this lesson, we all improve our oral English and the courage to speak another language other than our mother tongue.
When comparing this to most of the classes we had at that time, where we basically just went through the textbook and took notes, it was a thousand times more interesting, and of course, meaningful. Actually, from this lesson, I came to the conclusion that it is not so difficult to learn English if we talk more in it And L also learned that English can act as an interesting and useful tool in communications with foreigners if we’re good at it.