A single-member LLC is disregarded for income tax purposes. That means that, if your company is a single-member LLC, you and the company are one and the same. You can't sell anything to yourself, and you can't give yourself a loan.
A business is required to issue Form 1099-NEC for payments for services, not payments for goods.
You should consult a local accountant to get some guidance on how to keep proper accounting records for your business, and how to report the business on your tax return.
