How do I attach a zipper to my sweater? Do I need a sowing machine?

No, you don’t need a sweing machine, it can be done by hand. The instructions in the finishing book I used the last time I did a zipper called for three steps: basting the zipper in place with thread, stitching the inner edge with yarn, then securing it by backstitching the whole thing with thread. I’m sorry I can’t be more specific, but my mom has the book right now!