즐거운 시간

"가 봤어요" is grammatically correct but means "try to go without a previous plan (even though I expected whether it would be good or not)" I think the main goal of your trip was to go to B.A.P concert. In that context, "갔어요" is better for your writing.

"살다" can be used to mean "live in house or city for a long time." If you want to say "stay" at an accommodation such as hotel, hostel and B&B during a trip, "묵다" or "있다"  can be said.

"슬펐어요" is correct expression in terms of grammar and meaning. However, I recommend "아쉬웠어요." for this sentence. "아쉽다" can be said, when you "miss something which just ended or disappeared" or you "feel lack of something which was there." I think when you express your feeling after the concert which you had anticipated, "아쉬웠어요" is a little bit better expression.

I think your writing is great in terms of grammar and has no problem to express yourself.

However, if you try to combine short sentences into a combined sentence, you can write more elaborated and natural sentences.

For example, 

날씨가 추웠어요. 그런데 기분이 아주 좋았어요. 

==> 날씨가 추웠지만, 기분은 아주 좋았어요.

모스크바에 차로 갔어요. 그리고 좋은 호스텔에서 있었어요.

==> 모스크바에는 차로 갔고, 좋은 호스텔에 있었어요.

Good luck for your learning Korean.

즐거운 시간

문법적으로 거의 완벽하네요. 정말 잘 쓰셨어요^^.

Hi, there! I'm James. You are a big fan of B.A.P. Good for you they had a concert there.

Your writing is grammatically perfect. It is impressive.