If you are doing it right and if you don't have a huge gearing skids should be fairly easy. At first they wont be terribly easy but you should at least feel like you;re getting somewhere with it, else you;re doing ti wrong. Lean forward a bit, extend and push on your back leg and pull on the front. That's pretty much it. Lean forward if necessary. The pulling is almost more important than the pushing.
Getting into the second pedal? Just kind tuck your foot into it as its coming around. This can be tricky, it gets easier.
Yes, there is such an adaptor, I forget which websites sell it but look around a bit and you shouldn't have a hard time finding it.