Are these sentence correct?

we usually use two “和” at most.  他们买了刀叉和勺子。 This is better.  we say 刀 instead of 刀子. if we want to say knife and fork，“刀叉” is better than "刀子和叉子"

2- 她减肥了她很好看

this is correct. we can understand it but it's spoken language. it's a little weird. we will write "她减肥后变好看了" 

她减肥了 and 她很好看 are two sentence， you can’t say that without a suitable conjunction. 

3- 张文从来没吃快餐

张文从来没吃过快餐. 过 used in after verb means have done

4- 他们都打扮打扮在理发店

"打扮" is like more make up, we don‘t do this in barbershop. sometimes we say "她为约会精心打扮了一下" means 'she was dressed up for dating."  we rarely use it in barbershop or anywhere.

5- 国人买阴跌在zher

I don't understand what you mean. what is 阴跌？ zher  means “这儿”？

6- 电视台的记者是在这个城市 

记者 is a job or a group of people， you can't say it is in somewhere.  or you can say 这个记者住在这个城市。 

7- 记者人去旅游在世界

we rarely use 记者人, and it's not a word.  you can use 环游世界， means travel around the world. 

8 - 出租车的司机不在出租车

出租车的司机 is not a person， it's a group of people.  it's not possible that every taxi-driver is not in his taxi. 

这个出租车的司机不在出租车上。 

9- 他丢三落四他的钱包在我家

丢三落四 is an adj. and it can only used to describe people.
10- 我们想看看电视

我们想看电视， 看 is a verb.  看看 is intransitive

11- 早晨锻炼的人很多

12-人是很懶惰

人很懒惰 

13- 我们要毕业了
14- 足球比赛快要开始了

11,13,14 correct
15- 你们是快要开始了

I don't understand...

Hope this can help you