How to Ask for Diversion in a Petty Theft is It the Best Option

My question involves criminal law for the state of: Florida

If I want to ask for Diversion, should I plead "inocent" (not guilty) or "no contest" first?

Is Diversion the best option I have to keep clean my records? I think I'm guilty but I must have a clean record for my work.

Always plead NOT GUILTY unless you are advised by counsel as to the implication of doing otherwise. I believe most of the Florida diversions are pre-trial, in which you're probably not even required to make a plea. If you plead NOT GUILTY you can always change it later. NO CONTEST is for all intents and purposes pleading guilty (as far as the criminal trial goes). Don't do that again without knowing the impacts.

If NOT having a criminal record is essential, you'd be well advised to consult with an attorney.