I posted a simple endless runner example awhile back asking for help with the jump. You may find it useful. I just move the scenery back to the other side when it goes off one end, but I wasn't trying to make varying platforms at the time. You would probably want to create random platforms and scenery at one end and destroy it at the other. Note that the fix ramones posted is better than my original.
Making player surge towards center of window
There is another example of a vertical scroller here:
Vertical scroll platform
I'm sure there are others in the how do i FAQ and other threads, but this should give you a start.