Yes, you have the procedure a little bit off. You can do a trial by declaration. if you lose that you can ask for a trial de novo in court. Or, you can pay the fine and go to traffic school. Good luck to you.
I believe you both have the procedure off a bit. Either way, trial by declaration or request for traffic school, you pay the fine although it is called bail when you do a trial by declaration. The only way to avoid paying bail is to go down to the courthouse yourself for your arraignment when your appearance date comes up.
As my colleagues have indicated you can file a TBD but you are required to pay the bail/fine at the time of filing. If you are found guilty you file a Request for a Trial de Novo. Traffic school will still be available.