About the cars

Are the cars brand new? Can I be sure about the maintenance of the car that I rent? Can I go abroad by rental cars? Can I pick up and return the car at the airport? Can I rent a diffrent type of car that is not seen on your website? Can I return the car in any town I want to? Do I get the car with a full tank? How long can I rent the car? What do I need for contract? Will I get the car that I reserved?