hd issues

Hello to all, I hope you are having a good day. About a week ago my imac would not boot up. So i took to the internet to figure out what the problem may be and came across some useful information. I can boot up to disk utility and i see the hard drive and everything but once i start running...

I am hoping someone can help me. I just upgraded to the 2017 imac from a time machine backup. Before doing so I had around 200 GB's of free space but now my new system is completely maxed @ 1 TB! The system storage shows 289 GB's being used and I do not know what for. I can identify all my other...