The most important number in personal finance is time. Plug in your initial amount, monthly contribution, expected return, and horizon. See the hockey stick. Then see what happens if you wait 5 years to start.
7% is a reasonable real (inflation-adjusted) long-run return for a total-market equity portfolio. 10% is a nominal return benchmark. Use what matches your scenario.
Not financial advice. Compounds monthly at the annual rate divided by 12. Real returns will vary.