Chasing the same dream man. My parents initially planned that when they moved to United States. Plan was to build up a self sustaning Commercial RE portfolio. WHile this isn't S&P or NASDAQ, i feel like it is a similar concept. the money you put in, helps your investment grow.
For me, I mainly use the stock market as short term gain (most people would advise against that and rather you do long term investments years down the line). But I see it as a way to hold my liquidity that gives a better return than a savings account would. When needed, I can easily transfer it to other investments. Main goal my dad always wants me to keep in mind is double net worth, and invest in as much as you can. The plan is to have trying not idle cash since thats how money it all gets spent.
Some things I currently do are invest in commercial real estae with the family business and dable in the stock market. One good tactic that I feel like is over looked (especially with people my age or atleast people that I grew up around) is that owing a home. For example, most people in my area in Dallas spend $2k/month for a standard 2bed 2 bath apartment. During the market decline in March 2020, my brother and I invested in a home for $350k. Mortgage is similar to that of our apartment. It averages about $2.4-2.5k/month. We plan on living here for a about 5 years, pay off as much as possible while working on improving the house. Once the value is appreciated, we'll sell it, pay off the loans and have a good profit. It'll be a big initial investment, but rather than paying rent, we pay "rent" to ourselves which pays off the mortgage. Once we sell the house and pay off the loans, we'll at the least get our money back for 5 years of rent. So basically living for free for 5 years at the end of they day.
I kinda went on and on but let me know if this makes sense! I read this book called "Rich Dad Poor Dad" by Robert Kiyosaki which is pretty inspirenational in itself. Fairly easy to read. Y'all should take a look at it!