I WANT!

I can't sew...there I said it...I can't. I haven't done anything related to sewing my own clothing because I can't even make a pillow have straight seams :( I used to "sew" with my step mom which consisted of me cutting thread and the one time I tried to cut a pattern for a dress she was making me I cut it wrong and it turned out so badly I never wore it. But I WANT to make my own clothes, or at least be able to fix a hem in a dress. I have this amazing 80s shirt-waist dress that I found locally and I would love to wear it but its very long, almost to my feet but I want it to be just below the knee...well its been sitting in my closet for almost 2 years and I haven't been able to wear it because I can't fix the hem. I even got a cute little "beginner" sewing machine as a wedding gift and I've never even turned it on. I'm scared to death of messing up my lovely dress but I don't know where else to start. I did buy some scrap fabric at an antique store the other day but I wouldn't want to start with that either because of the age. I see so many beautiful rockabilly style dresses on etsy and I want to have some of my own SO bad! Any suggestions for a good "beginner" fabric or pattern?