The key to getting wealthy over a lifetime, even with modest income rests on three basic tenets:
1. Spending less than you earn.
2. Investing your savings in a low-cost index fund.
3. Starting very early. In you early 20s.
This site does not have much advice for you on how to spend less and save more, but my twin brother, Mr. Money Mustache does. Check out:
Please view this entertaining (and highly educational) video:
And finally, here are Mr. Money Mustache's real 2013 and 2014 expenses:
Consistently spending waaaay less than you earn is the most important of the three tenets. It provides us our critical compounding raw material. After that it is just a matter of how long the runway is (how many years) and the speed you're going (rate of compounding). Savings is the most important of the three.