While there are no competitions in the US (or outside of China- as far as I know, correct me if I am wrong here), Mainland China holds VEX GO competitions. Additionally, you are correct that there is no “Worlds” event, as these are held at normal (qualifying) competitions in Mainland China (similar to how the Kalahari Signature Event held VIQRC, VEXU, and VRC under the same roof this season).
Here are some photos from this past season:

(2022-2023 Asian Open held in Xi’an)
(15th APAC Robotics Signature Event Playoffs held in Macau)
For the 2021-2022 season, Tournament Champions, 2nd Place, and 3rd Place were given out at the Asian Open. The banners were a teal color, which matches up with the VEX GO branding (Asian Open hands out their own custom banners instead of the RECF ones).
(VEX GO banners are on the bottom right).
I assume similar awards were handed out at other events this season too, however since none of the VEX GO events in Mainland China were posted to Robotevents, I cannot be 100% sure (because of this, I am not even sure if normal VEX banners were awarded for the other VEX GO competitions).
Here is a link to the rules used in the Mainland Chinese competitions, and a link to the rules posted on the VEX Knowledge Base. For this season, iirc they are using the same rules and competition “game” as in last season.
Since there are no VEX GO competitions outside of Mainland China, I recommend giving the VEX IQ Robotics Competition (VIQRC) a look if your homeschool group wants to compete in competitions. Both VEX GO and VEX IQ are great robotics programs, so whichever program y’all choose your VEXers will have a fun time!