Hi,
I did some sewing evening classes about 15 years ago.
If I remember rightly I managed to cobble together a skirt & jacket under the watchfull eye of the teacher.
Since then however I've kinda stuck to curtains and cushions !
For curtains you need to multiply the width - the amount depends on which type of pleat you want, if it's just a kind of gentle gathered effect 1+1/2 times the width is fine, allow 1-2 inch on either side for the hem and the same at the bottom, plus an allowance for the header tape (the tape makes it a total doddle)
If you're using a lining just sew it into the top and sides of the curtain (in case of shrinkage when washed)
The easiest way is to pin it, then iron it before stiching - that way it lies nice and flat and you get a good result. I always find it easier to work with medium to heavy weight fabric for curtains as they seem to hang better and any small imperfections (of which I usually have a few lol!) don't show the same. A really good pair of dress making scissors is a wise investment, as kitchen ones just pull at the fabric when cutting, I also have a 'stitch unpick' (a wee curved cutting device) which allows you to undo any mistakes.
There are websites and tonnes of books to cover the basics - try your library before shelling out cash. I'd also try to track down an instruction manual to cover setting tensions and maintenance, it'll save a lot of head scratching in the future.
Sorry for the ramble.
Good luck,
Karen