Cotton as you already know is best. A floral will show less mistakes, we all make them. Sew with a smallish stitch. Buy a self healing mat, large is best, a rotary cutter and extra blade or blades and a good 6 x 24" ruler. Practice using the rotary cutter, not real easy to use. An iron, plain or fancy is a must. Every seam you sew you must press.
I hope this helps. Welcome from St. Louis, MO.