i'm about to that myself, as i just bought a new pattern.
my BEST advice;
simplicity patterns.
they are the easiest.
i have the one (the # escapes me right off) with the dogs dressed up in patriotic, halloween and easter outfits.
that was by far the EASIEST pattern.
I'm 20, so i think you can do it
also; but the remnants at a fabric store.
Thats the best way to go.
The pattern will always call for more fabric than you need,
just keep that in mind
here are some dresses i made, my FIRST time attempting