While it's not always the case, I'm guessing that the 'young girls' in the fabric shop were found in a chain store, and probably not the best to offer advice. I would seek out your local quilt shop (LQS) and get some direction there. I'm not good with colors either, and I usually start with a pattern. Go to your library and look at some quilting books. Once I have a pattern, I pick out a fabric with colors that I like. Those nice fabric designers have done all the color coordination work for you. On the selvedge there are color dots used in the printing process giving you an array of colors. I then pick the fabrics for the quilt using the colors in the focus fabric. Sometimes I incorporate the focus fabric in the quilt, often in the border or sashing. Sometimes I don't even buy it!