Toge Inumaki is important too. His special cursed speech ability makes him stand out. Also, the principal of the school, Masamichi Yaga, is likely to be important as he is in a position of authority and has an influence on Gojo and the other students. There could be other characters like the members of different clans that also play roles in the complex web of the story.
The author's recommendation for a novel that could wake people up was " Livestream: My Leisurely Cultivation Daily Life." This novel combined immortal cultivation, live streaming, sect, and daily elements to tell the story of the protagonist, Lin Zun, after he transmigrated to the Xianxia world. In the live broadcast room, he showed his immortal life of subduing demons, eliminating demons, cultivating immortals, raising spirit beasts, and planting spirit trees, attracting the attention of countless netizens on Earth. The novel was well written and loved by the readers.
It's hard to pinpoint exactly where Gojo is at any given time in the manga. His whereabouts change as the story progresses and different scenarios unfold. It could be in a supernatural realm, a mission site, or interacting with other characters.