Ignore the 700GB of Other. Other is just Apple’s way of saying it doesn’t know what applications these files belong to.
Typically a 1TB drive that is close to being full has lots of media files: movies and other video, music, and photos. To quickly determine if this is your issue open your personal folder and find the Music folder. Select it and get info. Make a note of how much space it is using. Move to the Pictures folder and do the same.
It is easy to move music and video to an external drive to free up that space. Moving pictures is a bit more problematic if you are using Photos and syncing pictures over iCloud. If so you’ll have to keep your Photos library on the internal drive. If not that folder can also be moved to an external drive.