The AD9851 is a DDS chip that accepts a clock of up to 180 MHz and generates a sine wave output anywhere between millihertz and half the clock frequency. Without some supporting circuitry around this chip including a CPU to drive it you will not be doing much.
Please read the data sheet for the AD9851 again
Once you have the control circuit built then you can generate a range of frequencies and perhaps see the response of RF filters using your oscilloscope.