Both examples of (A) are correct. "Went to" would be more 白话, while "attended" is a little more formal. In my opinion, both examples of (B) are ''correct but not common." That is, both would be considered grammatically correct but not the way the idea is commonly expressed. I would say, "This is my opinion of this city" or "That's just my point of view," (assuming the listener knows what the topic of conversation is). I would use "point of view" when referring to an idea or a concept rather than something concrete, like a city. ("This is my point of view on the subject.") This is only my preference. Others may not agree. One other thing. Unlike Chinese, English does not like to repeat words in close proximity, like ''this" in the second example. So, I'd probably say, "This is my opionion of the city,"omitting the second ''this"' in ths sentence. (BTW, "Which sentences ARE correct?")

They are all correct for part A.- we would use either of these but 'I went' is more common. 'I attended' is more formal part B - We wouldn't normally use this is at the beginning, I would say 'my point of view of this city is...'