My sister and I paid a visit in Hangzhou last weekend.A frie

My sister and I paid a visit to Hangzhou last weekend. A friend of my sister's, Lily, who worked there, served as a guide that day. It was the first time that I visited Hangzhou and I was really excited. In the morning, with Lily accompanying us, we went to the West Lake. Wow, there were so many people enjoying themselves around the lake. Following Lily's advice, we went boating on the lake first, then had a walk around Sudi and took many picture. I took us over two hours to cover it and we were awfully tired. After having a wonderful dinner, we had to say goodbye to Lily. What an unforgettable experience!
详pay a visit to sb./ sth.固定短语
Lily, who worked there, served 非限制性定语从句,两头有逗号
It was the first time 第一次第几次必须有定冠词
the first time I visited Hangzhou这里不必用过去完成时态
and I was really ...第一次去玩,所以（不是“但是”）我很兴奋
Wow, there were so many people 这仍然是在叙述过去,所以保持过去时态
so many people enjoying themselves 很多人在游玩（给他们自己找乐,不可能是“他们给我们自己找乐”, ourselves有误）
Following one's advice, we... 这里是句子主语”我们we”主动听从Lily的建议
we went boating (go on doing sth 是继续去做另一件事, 这里刚到,什么都还没做,不可能“继续”
It took us two hours (两个小时,复数,hours)
we were awfully tired 累得要命,非常累,需要一个程度副词awfully
What an unforgetaable experience 感叹句, 多么难忘的经历
希望对你有所帮助.

第二行sister's 改为sister。第三行在first 前加 the。第五行there are 该为 there were。第六行Ourselves 改为themselves。第七行的went on 把on去掉。第九行把hour 改为 hours。 倒数第二行把最后的冠词an 去掉。
纯手打，望采纳！