Also since you keep mentioning earned income. Are you thinking of when you are an employee on a W2 the employer deducts 6.2% Social Security from your wages. But they don't deduct that from unemployment or other income like interest and dividends. That is not the same as paying tax on the Social Security benefit checks you receive.
Yes you don't pay SS out of unemployment checks but when you start receiving Social Security benefits then all your income is used to determine how much of SS will be taxable (up to 85%).
Here is IRS Notice 703 form. It might help you.
https://www.irs.gov/pub/irs-pdf/n703.pdf
You don't enter the 703 on your return. The 703 is a worksheet for you to see how much of SS is taxable but it can be tricky to fill out and you might not come up with the right amount.
