I filed my personal taxes for 2024, and they were accepted. However, I forgot to add my business (this is the first year I have had it). What should I do?

You will have to amend your tax return.  Don't make any changes until your tax return is fully processed, which means you have received your refund or if you have a balance due, it's deducted from your account. If your tax return is pending, don't make any changes. 

Once your tax return has been processed, you can prepare your amended tax return. Since your business is a single-member LLC, your profits and losses are reported on a Schedule C. 

Refer to the TurboTax articles Where do I enter Schedule C?, How do I report income from self-employment?, and What self-employed expenses can I deduct? for more information regarding filing taxes for your business.

Also, you can review the TurboTax articles LLC Tax Filing Rules and Limited Liability Company Taxes for more information regarding LLCs.