How to make a lined bag.

I find this complicated.  You lay the lining down first ( right side up) then put the zip up. Then outside fabric right side down . Sew the edge getting close to the teeth of the zip - use a zipper foot. Iron. Repeat on the other side of the zip. Open the zip. Sew all around the outside leaving a gap in the lining to turn it through. After turning sew up gap . Voila!
It makes a lovely bag.