For IRS purposes, you are only required to file a tax return (in this case, a partnership return) if your business is ongoing and active. If you opened the business, looked for customers, and the business was ongoing with a profit motive, you might be able to file a return to report your expenses, and maybe get a deduction on your regular taxes, even if you never got paid by any customers.
However, if the business was never active (an ongoing trade or business), then you would not be required to file a federal return either for 2023 or 2024.
Also, if you applied for a federal EIN for the business, you do not have to cancel it officially, but you can't use it for any other business (if you start a new business some time in the future, you need to apply for a new EIN). If you never used the EIN, you have the option of canceling it, but this is not required.
https://www.irs.gov/businesses/small-businesses-self-employed/canceling-an-ein-closing-your-account
However, this is all separate from any state requirements. A state may require you to pay a registration fee, annual fees, and/or a dissolution fee, for your LLC. If you fail to follow state rules, you might have problems in the future if you try to start another business.
