about the zipper: my generic advice is think real hard about how it works, with all the folds involved.
Assuming there's no flap over it, the easiest way to do a good job is to put the right side of the zipper to the right side of the fabric, matching the edge of the tape to the edge of the fabric, with teeth inside:
Stich, then fold so the teeth are in the gap and stitch again:
Do the same on the other side, and install a slider:
If there is a flap, you can do pretty much the same thing, either inserting a seperate flap piece between the shell and zip, or by offsetting the zip teeth from the edge before doing the top stitching.