It's a car trip for most. There is an airport here, but who can afford to fly into such a small town. Amtrak comes into Guadalupe, eight miles to the west, but no car rental there, nor reliable public transport. Greyhound and Amtrak connecting bus service do come to Santa Maria.
Sorry to say it's a car town. Public transportation here is circuitous and for those without any other way to get around. Walking is not usually appealing becasue everything is spread out along a long North/South street for the most part. Bicycling is possible and very delightful in the surrounding countryside, long distance riders only.