Hello, I was wandering if one is allowed to go to an amusement park during the 9 days. I want to know the answer halachikly. Because my parents say I can’t and some people say I can. So I would like to know what the right answer is. Thank you very much for taking time to answer my question.

The mishna in Taanit teaches that once the month of Av begins, until after Tisha B'Av, one is forbidden to engage in activities that make one joyful. The Shulchan Aruch (Orach Chayim 551 2) cites specific prohibited activities but other activities are also forbidden if they make you personally joyful (Shu"t Noda Bihuda Tinyana Orach Chayim 105). What is a day at the amusement park for you? A fun day that you look forward to or just a not-bad way to pass the time? If your parents feel that you shouldn't go it is likely that they know that it is a fun activity that should be postponed until after the Fast.