How can I build wealth at 18?

Hey! I want to get ahead of the curve on my finances while I’m young to build wealth asap. I’m fortunate enough to be able to attend university next year which will hopefully land me a six figure job only a couple years after graduation. But for now… I want to grow as much as possible while I’m young. Would it be wise to buy index funds? I’m making roughly $700 a month online while a full time student (I’m very frugal as is). I know I need a strategy to grow which is where I ask for advice. Any financial tips would be welcome!