One possible version:

Yesterday I paid a visit to a model high school, together with my frienD．It's very big with a beautiful fountain in the center of the schoolyard．

We started our visit from the main building．First we went to the lab building where some students were doing experiments．Then we entered the lecture hall behind the lab building and saw many students listening to a lecture given by a professor．Opposite to the lecture hall was the art center．There we watched groups of students playing musical instruments．Finally we arrived at the playground at the far back of the school．Some boys were having a football game, which was so exciting that we couldn't help cheering for them．It was really an impressive visit．