Before you head out for the first time try leaning against a wall or in a doorway and clip/unclip a few dozen times just to get the feel of what it takes to get in/out of them. I especially recommend this if you're transitioning from Clips and straps since the motion to get out is a twist vs straight back.
Just remember to unclip before stopping and always lean towards the side you unclipped and you'll be fine. It becomes pretty natural pretty quickly so take your lumps and don't let a trip or two to the ground discourage you.