Q. What is the most amazing thing about your country?
박: I personally think there are so many convenient stores in Korea. it’s so amazing!
(The word "personally" is somewhat redundant here as the other party already knows you are expressing your own opinion. / "It's" has to start with a capital "I" as you are starting a new sentence. / You have to use "convenience" to describe the type of store.)
*김: Specifically, what was amazing about you?
(This sentence sounds odd as 박 is not asking you what is so amazing about yourself; instead, 박 is asking why you consider convenience stores in Korea to be amazing. Correction: What exactly is so amazing about convenience stores in Korea?
박: I like the fact that they are open 24 for 7. so I can be there whenever I want.
(It sounds unnatural to write or say "24 for 7". Correction: I like the fact that they are open 24/7, so I can buy things whenever I want.)