A basic college degree takes about four years and you'll likely have to work your way from the bottom up to attain a high-paying job, and you may find out that you're unable to accomplish that last part.
Learning about trading, researching ideas, developing a trading plan, practicing under simulated market conditions, messing around until you have something viable, practicing more under simulated conditions, trading live, screwing up royally, practicing again in sim, screwing up some more, and attempting to master the psychology of working in an ambiguous and uncertain environment, takes about four years and you may find out that you're unable to accomplish that last part.
The order in which you attempt these things probably doesn't matter all that much.
The thing about trading is that you can find out pretty quickly whether it will be a long arduous struggle or whether you're likely to get on the fast track to success (consistent profitability in less than a year). As Surf knows, the TopStep combine is an ideal approximation of the reality of trading for a living. If you think you have what it takes, give that try; I believe you can even do a practice combine at no cost.