When a key is pressed the corresponding Row flip-flop should get a LO stored in it. To take the flip-flop output back HI, simply press a button in a different row. It should be LO before the trigger point, go HI, then appear to go back LO and back HI in a random pattern. This is the phenomena of 'Switch Bounce'. Channel 2 will show you when the Flip-flop responds.
Different switches bounce differently.
What you get may not be like what someone at another lab station gets, and the waveforms will change each time you press the key. Repeat the three step process above a few times to get the feeling of what the switch is doing. Keep repeating the process until you have a good sample, and then download it. The Scope Waveforms you need to collect You should collect several sets of scope waveforms. At least one set showing the Clock bouncing and Q changing states more than once.