Many of us (me included) came here with little or no detailed understanding of how leases work.
You’re at a distinct disadvantage until you understand how leases are constructed / calculated.
This will give you a starting foundation: How To Calculate Lease Payments By Hand — LEASEHACKR
This is also helpful: LH Calculator and how to use it
Some people don’t have the interest in spending the time, which is fine. There are also a number of reputable brokers here (see Marketplace) who can help you with your transaction.
Broadly speaking, any broker fee you pay for the service is insignificant compared the thousands and thousands of extra dollars that a dealer can extract from an uninformed consumer who puts a deal together with insufficient information.
Remember, a given dealer does this dozens / hundreds / thousands of times a month, compared to you being in the market once every X years. Be careful out there.