TAKE you measurements!!! The sizes on the patterns are not translatable to ready to wear! Make you clothing to match your measurements, not the size you buy in the store.
I taught myself to sew. The first "big" project I tackled was a swing overcoat, that was about 18 years ago and I still wear it and I am complimented on it everytime. I find it odd that strangers will comment on it everytime.
Any way.... back to topic, if you can piece together a quilt, why not a dress? Most of us started sewing clothing, go for it!