Hey there! Since you have a physical disc of Destiny 1, that means it is not being read properly. If you are receiving the trial mode message, this means that you have a damaged disc or your optical drive is broken. Did you check your disc for scratches along with cleaning the disc with alcohol?
It's not Trials mode, it's Trial mode. The first person to answer in this topic linked below seems to understand the issue. https://answers.microsoft.com/en-us/xbox/forum/all/destiny-1-stuck-in-trial-mode/201fcbc6-7422-45ed-8a8d-0ba5f61b3a37