You can use an Array to store the different actions you want to happen, and on start of layout randomnly select one, or put "Wait N seconds" and call more than one.
Also, you can put them as Groups (Unactive on Start), and activate them as needed.
Or, using a local variable, select a value floor(random(0 to N)) with N as many events as you have, and compare the local variable and activate the one which equals the value created.