Here are some links that might help you better understand and enjoy Sumo wrestling.
Sumo Terminology. Those of us who enjoy Japanese Sumo often use the Japanese term for various Sumo related words. For example Basho = Tournament, Rikishi = Wrestler, etc. Find more at this site: https://en.wikipedia.org/wiki/Glossary_of_sumo_terms
You can watch Grand Sumo wrestling matches on the internet via channels such as Sumo Jason or from NHK on their Grand Sumo Highlights page. Sumo Jason usually offers several bouts per day while NHK posts a daily summary at the end of each day.
Sumo Jason often has a free contest to enter for each tournament while NHK has started streaming live sumo wrestling on the Sundays of each tournament (usually Day 1, 8, and 15).
bigSUMOfan.com sponsors some of Jason's contest prizes:
Another great Youtube channel, until early 2023, was Kintamayama. He provided summary videos for each day often with entertaining commentary. His channel is no longer offered as of mid 2023 but hopefully it may be available in the future.
This link takes you to the Japan Sumo Association website English version: http://www.sumo.or.jp/En/
You can find the tournament roster and matches here: http://www.sumo.or.jp/EnHonbashoBanzuke/index/
For those who enjoy podcasts you have to check out Sumo Kaboom . They cover the tournaments and so much more. Very entertaining. A new episode most every week even between tournaments.
John Gunning is a sumo sports writer for the Japan Times and an NHK sumo announcer in Japan (not to mention an ex-wrestler) who writes some good articles in English. Find his Japan Times articles here: https://www.japantimes.co.jp/author/john-gunning/
This link by the Japanese NHK channel demonstrates many of the common winning techniques. NHK also broadcasts/streams many of the bouts, sometimes live. https://www3.nhk.or.jp/nhkworld/en/tv/sumo/techniques/
NHK also has some excellent 2 minute videos each focusing on a variety of topics. Highly recommended. NHK Sumopedia
Want to read more in depth about the wrestlers and keep up with Sumo between tournaments? Tachiai.org is a great blog website to give you even more detail and perspectives from some very informed bloggers. You can find them here: https://tachiai.org/
Check out USA Sumo to find information on the annual US Sumo Open held in California in the spring.
Here is a really cool chart by Fred Pinkerton. It shows wrestler movement up and down the banzuke from tournament to tournament.