What is the minimum weight load for a CDL license?

There isn't one. A CDL is required for vehicles with a Gross Vehicle Weight Rating of 26,001 lbs. or more (with the exception of vehicles exempted from CDL requirements under the federal regs, such as recreational vehicles, emergency vehicles, military vehicles, and farm vehicles), but also for vehicles of any weight which are either designed to carry more than 15 persons (including the driver) or carrying sufficient quantities of hazardous materials to require the display of placards under FMCSR law.