Most lenders set the first payment date for 45 days after you sign the loan paperwork. And while there typically isn't much flexibility with this date, you might be able to choose your preferred date if it's close to the 45-day mark.
Remember: Your loan will probably include a grace period of 10-15 days—but it's best not to miss a payment if you can help it. Missing your first car payment can signal to a lender that you're a risky borrower, you might be charged late fees, and it could impact your credit score.