warranty on the usbc to lightning cable that came with my device?

Hi there! Your iPhone 11 Pro, along with all of the accessories in the box (assuming you bought it from Apple, a carrier, or a retailer -- not second-hand) are covered against workmanship and design defects for one year under Apple's limited warranty. However, in the case of normal wear and tear over years, you would likely need to purchase a new cable. See below:

Apple Inc... warrants the Apple-branded iPhone... hardware product and the Apple-branded accessories contained in the original packaging (“Apple Product”) against defects in materials and workmanship when used normally in accordance with Apple's published guidelines for a period of ONE (1) YEAR from the date of original retail purchase by the end-user purchaser ("Warranty Period").

The full warranty policy can be found here: Legal - iOS Warranty Document Us - Apple