You quilt, you already know how to sew!!!!
Get a pattern as suggested, the enclosed directions offer step by step instructions and are usually user friendly. I need to tell you, though, the seams are 5/8 inches not the 1/4 inches that we are all so used to. You will do great!!!!!
If you get into a bind with some direction, just post a question and I know one of us can help you. Years ago, I sewed garments (even took Sewing in school when that was the thing to do). Those skills I learned transferred over to quilting. And, I think your quilting skills will transfer over to making garments. Go for it , girl! You'll do great!