I agree with everyone that you really must read through the directions thoroughly before starting. I also think that it would be a good idea to do a really simple and small pattern first to get the hang of paper piecing. Maybe one of those little "mini" packets. That way you can get all of those mistakes out of the way on something of lesser value. And, there will be mistakes and those errors usually involve cutting. I've never done a precut so don't know if they include extra pieces to allow for errors, but that might be something to check. I say give it a try...you may love it as much as I do.
Also, STAY OFF OF THE PHONE while trying to figure it out. Distractions can be fatal. I think all of my goofs can be attributed to trying to multitask while paper piecing.