Learned to sew when I was a kid. Started out with doll clothes & then just kept advancing to bigger & better. Teach him how to use the machine first & get the concept down. What does what, needle sizes, don't use the good scissors on anything but fabric. Lots of easy bag & tote pattterns out there that would be easy to start with. I taught my oldest son how to use my machine & to hand sew. Came home for lunch one day & he was sitting in my sewing room, sewing up his finger. I nearly passed out. I asked why he didn't go to the emergency room & he said he didn't want to mess up his safety record. Men! At least I taught him well. He had a nice blanket stitch of black thread down his finger & healed wel. Never know where they will use their skills.

More power to your son for wanting to learn a great life skill!