The difficulty of putting together a kit car depends on the specific kit, but most people can expect to spend hundreds of hours of work and perform research for installing specific components. Some car kits also require welding, which requires training and certification in many places.
Cars require batteries, so people building kit cars need to make sure they can work with electrical components safely. Systems also require drivers to read complex diagrams, which might require guidance. In addition to the time investment kit cars require, builders also likely need special equipment. Even small kit cars have engines too heavy to lift without proper machines, and many kits need extensive tool kits.