You can't contribute to an IRA unless you have compensation from work. If you work, you can contribute to an IRA up to the amount of your compensation. This can include part-time work as a Wally World greeter, and is allowed even if you declared retirement and are taking social security--but you must have compensation from working. There is no age limit to contribute to an IRA as long as you have compensation from working.
If you withdraw from an IRA (take a distribution), you report the gross income and pay income tax. You will get a 1099-R from the plan administrator. If you are over age 72-1/2, you have a requirement to withdraw at least a minimum amount (or more) based on the account size and your life expectancy. This is called a required minimum distribution (RMD). If you don't take the RMD when required, the penalty is substantial.
