Hi wizard Istanbul!

I need to choose between renting a car and the LRT. For that i need to know how many will it cost me to go from Ataturk int. airport to Tophane.
And i need to know if it’s easy to circulate by car in old Istanbul and if it’s easy to park.
And maybe you can advise me an agency where i can change my euros for cheap. I guess it’s expensive in the airport.

A big thanks for your answers!