how can my younger brother who is a junior in high school start preparing for the real world?

plz don’t say SAT prep

building web3 security infra @ getshield.xyz 🛡️ • commander-in-chief @ ancientwarriors.xyz ⚔️ • nf.td/eman • emanft_.twitter

have him work a month doing manual labor 50hrs/week

I bet he'll begin to appreciate things

chad.degen.eth // Current: BizOps @ Alluvial,
Prev: Cambridge Associates, 6th Man Ventures, Blockworks, Amherst Math & Econ /observations

Have them go to a poor country to build a school. Live with the families they are helping. 
Build real stuff, see people with real problems, appreciate much more.