I once bought a cheap roll of RA-4 paper. To cut it, I set up a paper cutter and marked the lengths I needed with pieces of tape. I could then pull out the required length, cut, and put the cut sheet in a bag. This is, of course, a time-consuming operation. I hope you're not planning to make a profit on your operation, since your profit will probably translate into a very low hourly rate of pay. If you just want to do this as a way to get cheap paper and help your friends do the same, of course, and you don't mind sitting in the dark for hours on end, this will work fine.
As for packaging, I seem to recall seeing light-tight bags for sale at
B&H, Freestyle, or some similar place, so you could check there (or at mail-order photo retailers on your continent, if you're not in North America). You could check a post office or office supply store for small boxes into which to put the light-tight bags. For smaller quantities, you might be able to collect used bags and boxes from your and your friends' darkrooms. That's what I did; I re-used bags and boxes that previously held boxed paper from various sources. I'd just cut up a few dozen sheets of various sizes then store the remainder of the roll until I ran out of the sheets I'd cut.