"sue right the fuck now" implies that this is a process that can just happen. had he said "you should look into finding a local pro-bono lawyer who is willing to see if your case would potentially result in meaningful damages, and pursue that if the damages recovered would be worth the time and resources involved in filing the lawsuit" then I wouldn't have said anything. Instead he just said "sue", ignoring all of the nuances that are associated with that.
if you call "having enough money to sue over one retracted job offer" as a broke, job-hunting, barely-past-internships person is simple you need to reevaluate your view.
Yeah dude. You have an exact understanding of every applicable federal and state law involved, including every piece of relevant case law and know exactly how cut and dry this should be. Lol. Any lawsuit, regardless of how simple it seems, is a shockingly messy and expensive process.