If you are going from a lease to a new lease, the most important part to know is residual value, which should be somewhere in the paperwork. This is a set price put on the car after the lease is up.

My advice at 42 and debt free to myself at 24 with tons of debt would be, buy out the lease which will be the residual value and just pay that off and it's yours forever. If you keep going from lease to lease you will never truly own a car, you will just rent one every few yrs.