The tension will make it harder or easier to get out, but not to get in. That's a matter of practice. The first time I had the shoes locked in, I was able to unclick in an instant, almost without thinking. But it took me about three weeks to become able to clip in without effort or any thought. If you're having trouble clipping in and it's only been two hours, you're ahead of the curve.
Here's a tip, but it's a difficult one. Line the cleat up over the pedal, while you're not on the bike. Push down will all your might, and you should be able to get the shoe locked in. That'll show you that it can be done, but it will also help you figure out or see exactly where the shoe needs to go over the pedal. ( Chances are the cleat should be under the center of the ball of your foot. )