You can cash out at any time, however, there might be big tax consequences. First of all, you can withdraw your contributions at any time since you have already paid the income taxes on them. Your first withdrawals from a Roth IRA are considered to be contributions.
If you wish to withdraw your earnings tax free, then they must be five years old, and you must be at least 59 ½ years old. Otherwise, there will be taxes and penalty to pay. There are a few exceptions as follows; you may withdraw up to $10,000 tax free for a first-time home purchase. It is tax-free if you withdraw after you become disabled. If you die, your heirs can cash it out tax-free if the earnings are at least five years old.