New in this world, some questions

Hello guys (sorry my bad English )

Looking to learn SEO, i have been learning from YT and free courses last 2 months, but always all YT gurus wants to sell you the course so can’t be objective about this, have few questions that can’t find;

-Should I work in passive incomes instead of work for agency’s?

-what’s your passive incomes and how many years you spend for it?

-There’s any YouTube SEO guru that doesn’t sell courses?