New Broker (Desking Tool Help Needed)

Hello all, in short i am currently in the process of starting my own auto brokerage to help students, teachers, and folks in the medical industry more confidently lease & buy new cars. (all people who i feel dont have the time or the knowledge to confidently shop for a car)

As a female in a very male dominant industry its tough to get answers when i ask so im hoping the experts here can provide some guidance and answers.

1. I have noticed at many brokers they use a desking tool. Im also certain that the brokers i have visited dont invest what it costs for a desking tool like MDESKING, so what do they use?

2. Is there a free desking tool that can help me calculate lease deals mainly on vehicles? Something that maybe auto populates the monthly residuals and money factors? Something that calculates manufacture rebates and things of that sort?

Does anyone have any insights as to how brokers actually make $ ? I ask because a few of the dealers i have already created relationships with in anticipation of this business venture have suggested the following comment... "basically you call us and tell us how much $ you want to make as the broker on the deal and we give you the total $ out of pocket and monthly payments on the vehicle your client wants"

These comments contradict some of my personal experience ive had when leasing cars from brokers.. again it seemed they already had the car (or at least the MSRP loaded in the desking tool and they adjusted numbers there to determine the price. They simply would call around to locate the car.

I apologize in advance for sounding like such a rookie...but its because i am.

Thanks in advance for your guidance and support !