You can fight the ticket, though you may have some problems.
In California, the definition of driving usually includes any movement of your car, no matter how slight. If you were parked on the wrong side of the road, your pickup had to get there somehow, and you say the officers saw you drive it away. The short distance from the place where the truck was parked to the correct side of the road would probably support a conviction for driving on the wrong side of the road.
There is something called a "necessity defense," but it would not apply in this case. It requires an emergency and no reasonable alternative, but you could have made a U-turn and parked on the correct side of the street.
You can show up for your court date and ask for a hearing, where the officer would testify. If you are eligible for traffic school, you can keep the ticket off of your driving record so your insurance company won't raise your rates, but you would have to pay the ticket amount plus an administrative fee, in addition to the cost of the traffic school..
Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like Avvo, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.
I agree with Attorney Marshall's answer and would add:
If you are ot eligible for traffic school or are determined to fight it - consider filing a trial by declaration first (some times the officer won't respond and you will win), then if you don't win, you can have a brand new court trial (some times the officer won't respond and you will win again). So you get 2 bites at the apple.
Good luck with your situation.