look at the button sketch that is part of the IDE
if you press the button, you can add an if()
if(button == HIGH) {
count ++ ; // increments by 1
if (count =>6) { count = 0 } ; // reset to 0 if it goes too high
}}
if count == 0 then normal reading
if count == 1 menu page 1
if count == 2 menu page 2
and so on.