Displaying more pages isn't hard..
The way your events are set up is not right..
Because of the way construct2 works, if you call the function two times in the same tick only the last will display..
You could try with a number counting up to what part of the conversation your in, but you have the destroying in the same function, which shouldn't be there..
You probably want to destroy on conversation end, but then you should let the computer know when that is..
There are multiple ways to set up something like that, but following a tutorial like the one I linked will teach you a lot..