The Hatsu Basho is January 8th - 22nd in Tokyo. My favorite way to watch it in the US is through the NHK News app which you can get on the Apple App Store or Google Play Store. You can watch each day’s highlights about a day behind. This works best because of the time difference. They usually offer some live broadcasts the first day, the halfway point and the last day. There are a few good sumo channels on youtube. Chris Sumo's channel is good place to start.