There is no advantage in either starting treatment early, or in delaying treatment. The appropriate time is when your symptoms are interfering with your life. The aim of medication is to improve the symptoms where you can manage with them, but not to get rid of the symptoms completely, that is, to use the smallest reasonable dose of medication.
The type of medication to start on is controversial, between a dopamine agonist (eg, ropinirole) or a preparation contain L-Dopa (Madopar or Siminet) You need to discuss these options with your neurologist.