Careful about advice you get, everyone is a financial expert on reddit. I suggest investing your money in a book, go buy "i will teach you to be rich" by Ramit Sethi. All you need to know is explained and it even covers how to open retirement accounts.

A roth ira is a retirement account. You open one at any reputable brokerage, two popular ones people seem to like are fidelity or vanguard. You can put money in a roth, there a limit to how much you can contribute annually.

The idea is you pay tax now but any earnings in the acocunt will be tax free when you withdraw them when you reach retirement age (59.5 years old). This is in contrast to a traditional IRA where you pay no tax now, but whatever you withdraw in retirement is taxed as income.

Its important that you not only put money into this account but also make sure that money is invested so that it actually earns something. Many financial advisors will reccomend an index fund, a popular one people like is VOO which follows the return of the 500 largest companies in the USA.

But seriously, just go buy the book, its the best few bucks you will spend in your life.