It depends on how old you are and how long you've had your Roth. If this is a Designated Roth 401(k) through your job then any employer match will be taxable. IRS doesn't allow employer matches to be deposited into a Designated Roth 401(k). They are in a pre-tax 401(k), meaning contributions and earnings will be taxed on withdrawal.
Contact your bank. They can probably tell you whether your withdrawal would be taxable.
As for your contribution, Investopedia has a good explanation at What Are the Roth 401(k) Withdrawal Rules?
An IRA is a private arrangement that you set up with a bank or broker. If this is an account from a job, it is likely a 401(k) or 403B, or some other type of workplace plan.
When you terminate service with that employer, you have the option of rolling over the funds into a private IRA or into the workplace plan of your new employer. Rollovers are tax-free. If this is a designated Roth 401(k) account, you would have to roll it over into a Roth IRA or a designated Roth account at the new employer.
If you want to cash out, you can withdraw the original contributions tax free, and you will pay income tax and a 10% penalty for early withdrawal on any earnings.