Find a beginners pattern that you like. It will tell you how much
fabric you need. Perhaps a small wall hanging or table runner
first because it will take less time to finish. Squares are easier
than triangles - no curves to start with.
Maybe start with fabrics that aren't so expensive, but ones
that you like. Using a sewing machine is quicker than hand sewing. Quilt shops fabrics are expensive, but they can be very
helpful for a beginner. You can buy tools & notions as you go
along -- a cutting mat and rotary cutter would be a start.
Buy a good reference book to learn basics or/and take a class for beginners.