If you can lift the front wheel and rear wheel independently this is a good start.
Before you start to try bunny hopping anything try this approach. Lift and place your front wheel on your chosen obstacle then as you roll forward lift and place your rear wheel on your chosen obstacle.
Then build on this by reducing the time between front wheel touching down and lifting the rear up. Aim for timing the second (rear) lift with the rebound of your forks/tyre.
After practicing many of these you will be able to do the rear lift before your front wheel touches down. Voilà, you have a bunny hop.