Manuel Márquez de León International Airport: This is La Paz, Baja California Sur—not Bolivia’s El Alto airport (LPB), which dominates much of the supplied material. LAP is close to Centro: use the official airport shuttle/shared transfer if its schedule fits (about 14 minutes; roughly MX$250 is the current quoted shuttle price), or take an authorized taxi and agree the fare before leaving. A pre-booked private transfer is needless for most arrivals unless you are going straight to a resort or travelling with a lot of dive gear.
La Paz bus terminal: Long-distance buses are the practical overland arrival, chiefly from Los Cabos and other Baja California Sur towns. The terminal is close enough to Centro for a short taxi/rideshare rather than an overpriced hotel transfer; walking with luggage in the heat is a poor bargain.