I started collecting social security last year and paid no taxes on it. I realized that I didn’t include this on my accepted return. How do I amend this?

If you already e-filed you have to wait and see what the IRS does with your return.   They might catch the error or might not.   If they do not catch it, then you will have to amend after the return has been fully processed and add your SSA1099 to the return.   For now, do nothing.  Do not try to change anything on your return.