Hello and thank you for your question. You can still contribute. I would recommend to look at traditional and roth IRAs, including a SEP plan since you are retired and self employed. Included links below for both options. The first one has to do with contribution limits and the second has to do with a SEP plan since self employed as well. Have a great day!
From IRS "IRA Contribution Limits"
Hi MikeysGirl,
You and your spouse (if married filing jointly) can now contribute to an Ira at any age. Your self-employment income does qualify as taxable compensation for purposes of an Ira contribution. This includes both the Traditional or a Roth Ira.
However, limitations do apply. In 2023, for a Roth Ira, your modified adjusted gross income can't not exceed $218,000 for Married Filing Jointly. In this case, you can contribute the maximum of $7500 for an individual aged 50 or older. If your compensation is less then $7500, then the maximum you can contribute is your compensation.
https://www.irs.gov/retirement-plans/traditional-and-roth-iras
https://www.irs.gov/retirement-plans/amount-of-roth-ira-contributions-that-you-can-make-for-2023
For an IRA contribution. If you only have self-employment income you can only contribute up to your net profit reduced by the deduction allowed for one-half of your self-employment taxes. See IRS publication 590 http://www.irs.gov/pub/irs-pdf/p590a.pdf
What kind of business did you form? Is it a self employment, freelance, sole proprietor or Single Member LLC etc. And if you are married and both work in the business there are other rules to consider. You might see an Accountant or tax professional to get things set up right the first year.