If you have any other income, your social security may be taxed. This includes investments, IRA withdrawals, and so on, and happens at any age.
If you have income earned from working (either a W-2 job or self-employment) after you declare retirement, and before you reach your full retirement age, your social security benefit will be reduced. (And then it also might be taxed.) The IRS or social security administration don't track your hours worked, they go by your W-2 or your schedule SE. If your income for 2022 is over the limit, your SS benefit for 2023 will be reduced.
https://faq.ssa.gov/en-US/Topic/article/KA-01921
https://www.ssa.gov/pubs/EN-05-10069.pdf
The earned income threshold is $19560 ($1630/month), and the benefit reduction is 2 for 1. For example, if you earned $5000 per month from self-employment after declaring retirement in 2022, your 2023 benefit will be reduced by $1685 per month. (5000-1630=3370/2=1685)
