Heya,
As Chicken already said, for a checkpoint, you just write 'checkpoint' on the top line of a sign! If your map gets accepted it'll be formatted appropriately.
For an 'endpoint', or finishing pressures plate, you use a piece of wool that matches the difficulty (green for easy, yellow for medium, red for hard, purple for expert, orange for insane) and a stone pressure plate on top, usually with some kind of sign or arrow that suggests to the person parkouring that it is, in fact, the end of the map!