If you have an hour to spare and want to learn about the worlds most successful art dealer Larry Gagosian the New Yorker has done a 2023 profile that showcases his grit and hustle to break into the art world from Los Angeles into the global phenomenom he is today:
https://www.newyorker.com/magazine/2023/07/31/larry-gagosian-profile
other profiles mentioned are from 2009 in The New York Times: https://www.nytimes.com/2009/03/08/business/08larry.html and a 1989 piece that was republished online in 2019 from the Village Voice that can be read here: https://www.villagevoice.com/7-days-larry-gagosian-arts-bad-boy/
Any aspiring gallerist should read all 3.