Bamako doesn't have a metro or formal bus network. You get around by taxi or minibus.
Taxis are the default option. All are painted yellow. There are two types: shared taxis (with a sign on the roof) that pick up multiple passengers along a route, and private taxis (no sign) that take only you. Shared taxis are cheaper; private ones cost more, especially after dark when rates double. Most drivers speak only French.
Minibuses (locally called Dourounis) are green and run fixed routes. They're cheaper than taxis but crowded and can be slow. Avoid them at night — poor lighting on the roads and unreliable vehicle lights make accidents more likely.
Car rental is available, but the vehicles are generally no better than the taxis. Most rentals come with a local driver, which is genuinely useful given Bamako's traffic.