A capacitor that is fully charged will read open because of the very high resistance a capacitor has when charged. If want to test capacitor if it is working short the to ends of the cap .Test with an Ohm meter

.The resistance will rise as it charges because the meter is applying a voltage during a resistance measurement .Low value caps will charge very fast .To fast to notice the resistance rising. High value capacitors will charge slower. You may even see the resistance rise as they charge. But the resistance will always go to infinite on a fully charged capacitor no matter what value it is . But it won't tell you the value of that capacitor.
If you press the yellow button you should be able to toggle to capacitance testing. The symbol right of the

symbol is capacitance.
Why an expensive meter like Fluke doesn't have mode or select written on the mode button baffles me .