If I work for UBER do I have to file the FLorida Tangible Property Tax return DR-405?

Yes, you are required to file a Florida DR-405 Tangible Property Tax Return.

Anyone owning Tangible personal property on January 1 must file a tax return by April 1 each year unless you were notified that the filing requirement has been waived. Every new business owning tangible personal property on January 1 must file an initial tax return. In any year the assessed value of your tangible personal property exceeds $25,000, you are required to file a return. Taxpayers who lease, lend or rent property must also file a return.

Tangible personal property is everything other than real estate that is used in a business or rental property, and includes vehicles.