I hate stretch jeans. After a while you get puffy knees & butt. There aren't any brands available for women that don't have stretch fabrics in them now. Men can still get traditional jeans. Like most clothing today it's nothing but cheap junk made overseas.
I make my own. Been sewing since I was 8 (my Grandmother taught me) & have made a lot of my clothes over the years. I worked in a garment factory for 11 years. I un-sewed a old pair of jeans that fit, made a pattern & I make my own right down to the rivets, just like factory made. I have leather making tools, so my press machine works to set rivets. Years ago I found a place that sold rivets for jeans, the same as the factories used. I bought enough to last me my life time. I also found the same thread, they used in factories, in the same large spools.
As a teenager I could not find size 0 or 1. The smallest the stores carried back then was size 6. So all my jeans had to be altered anyway. Years later I was able to find size 3. Even today I have trouble finding my size in local stores.
One thing I no longer do is flat felled seams. I sew the leg seams, right sides together as normal, overlock the seams & then fold the seam to one side & do a double row top stitch. Sometimes I do embroidery on the pockets before setting them or on one leg. I can still find traditional, non-stretch, jeans fabics at Jo-Anns.
Don't be afraid of the zipper. Use the drawing on the zipper package to trace the stitch lines. It'll make it easier for you. Use a jeans needle & go slow when stitching the belt loops on.