Overview is here https://www.irs.gov/retirement-plans/roth-iras , but generally 59 and 1/2 is when you can start taking distributions without penalty.

Money in an IRA doesn’t automatically “multiply” as you say. You’d need to invest your contributions into something, like a stock or mutual fund

You can take the principle out without penalty. Profits need to wait until 59 1/2 to be penalty free.

https://www.your-roth-ira.com/withdrawing-roth-ira-principal.html