You’re setting yourself up for a good whoopin. You need to learn about leasing including how to make all the calculations. You’re allowing the dealer to control the deal. Bad idea! I suggest doing some research regarding sell price in your area. Also, get the MF buy rate, residual factor, rebates/incentives from Edmunds. You didn’t mention the vehicle year, your state, or sales tax rate.
At any rate, once you’ve collected and vetted all information, create a lease proposal like the one below and email it to the dealer. Always negotiate via email/phone.
You have to control the deal and be firm. Otherwise, they’ll chew you up. Knowledge breeds power and confidence. If this is not your cup of tea perhaps because you’re too busy with other fish to fry, I suggest hiring a broker. There are plenty of good ones on this site.