Burbank (Bob Hope) is in the northern part of Los Angeles, and a long way on a congested freeway.
The cheapest way is to use the Metrolink Train from the BUR airport to Union Station, and transfer to the trains that service Fullerton,and then a Bus or taxi/uber/lyft,
A taxi is over $100 and more expensive than LAX. Uber/Lyft would be cheaper, but still a lot, and the drive would be about a hour or more in heavy traffic.
I like the airport in size, much better than LAX, but not a good choice for getting to
Disneyland. Same with Ontario (ONT).