Central Makeni is small enough to walk. From the cathedral to the central market is ten minutes on foot, and most of what a visitor wants to see lies inside that triangle.
For longer hops — out to the University of Makeni, or to one of the chiefdoms around town — okada (motorbike taxis) are everywhere and cheap. Agree the price before you climb on; helmets are rarely offered but you can ask. Shared taxis run fixed routes along the main roads for a flat fare. Private taxi hire is straightforward but expect to negotiate.
If you are heading out to Mount Bintumani, Outamba-Kilimi National Park, or anywhere off the tarmac, you will need a four-wheel-drive vehicle with a driver. Arrange this through your guesthouse or one of the tour operators in Freetown before you arrive; renting on the spot in Makeni is hit-and-miss.