I had the same problem when I switched from a flat bar to a dropped bar bike. I took my bike to a park and practiced there. I didn't even deal with the clips (I had dual side pedals that are clip in on one side and platform on other). I suggest you start by putting the bike in your middle ring, so all you have to do is shift up and down the rear cogs. You may even practice that in a trainer if you have access to one. Get good at that, then learn to shift the front. Get good at that, then try riding with one foot clipped in and one free, then go to both feet. Give yourself time to adjust to each change.