Haven't done this for years, but some time ago I bought a set of pamphlets from Sailrite entitled something like "make your own xxx sails and win". They were a bit rough, but outlined the process of designing and then sewing up sails of all sorts. Incidentally, this does not involve the paper patterns that you mention.
At that time I had a 30' S&S design, and I built a spinnaker
and a storm jib
for her (sort of both ends of the sail spectrum). I lived in a fairly small house then, and the kite just about filled up the living room, establishing a limit on what I could reasonably build ! For your daysailor there would be no real problems. Incidentally, I did all the sewing on a 30$ second (Nth) hand home Singer machine. For dinghy
sails you definitely do not need a fancy Sailrite machine, nice as they are! Sailrite also had a booklet obout tuning and adjusting a home machine to optimize it for sailmaking, and it was very helpful.
The folks at Sailrite are very helpful for beginners, and don't seem to be greedy... they'll help you with your budget-driven choices.
Good luck with your efforts -- it's truly a great feeling to build sails, and then win a race
Jim and Ann s/v Insatiable II lying Gladstone Qld Oz