Cruiser boards usually vary in shape from traditional street boards and can vary widely in width, but generally are shorter than about 34 inches. Cruiser completes come with softer wheels, too. Softer wheels are an easier ride. Cruiser boards are generally not for doing tricks. They're transportation like longboards, but don't have the uncool factor that longboards got stuck with from the street skaters.
Shoes are probably the single most important thing in skateboarding outside of your skateboard itself. Function matters of course, but the judgement cast on you for your choice in footwear can be intense. Let us guide you.