Theres generally two strategies,
Go to school and specialize in a subset of knowledge that companies value, i consider knowledge in general valuable to society, but not all knowledge is valued/pays equally in our current economic system.
The other strategy would be to start your own business. It may help to go to school for this as well but you don’t have to.
If you are not either highly skilled and in a high demand job market, or owning your own business or other capital, its gonna be pretty tough and take a long time to climb your way up.
Both strategies will take some initial costs
Strat 1 being student loans, try to go in state and/or apply to scholarships.
Strat 2 being business loans,
In general, unless you have connections and good understanding of economics, its easier to try strategy 1 first, then maybe leap over to strat 2 once you have your footing.
strat one will be decent money and less risk.
Strat two will be higher risk higher reward and has the ability to scale pretty high.