I recommend beginning with Internet information searches and trips to any local libraries (which may also have videos available). If you do not learn well from books and web-surfing, then consider videos, classes and/or lessons.
Take good care of your materials and supplies. Cherish your needles and scissors. Indulge yourself on thread, get the best *suitable* thread for the project: silk for silk, cotton, for cotton, usually avoid 100% polyester except for 100% polyester fabrics.
I've always recommended *smaller* projects first. The basic "smaller" projects are doll clothes and baby clothes. You can learn nearly everything you'll need to know by working on such things with a minimal outlay for materials. Baby clothes and doll clothes with dolls can be donated to shelters. As experience and competence and confidence build, graduate to larger items.
Watch for pattern sales at places like Joanne's, etc., where they may get down to $1 each. Plan ahead.
If such are available in your area, purchase items to re-make. I coat can become a vest. The legs of large khaki trousers can be disassembled for materials for tailored multi-pocket shorts. A silk blouse can become a silk lining for a bodice.
I figure folk with good dexterity should learn to sew by hand first. They can learn the hand-finishing techniques while they're still doing wee projects. Then they can graduate to machine work, if/when machines are available. Nice "finishing" makes a world of difference. It's good to practice it from the beginning.