Dave,
you need to get the bulk roll into the loader in complete dark. Whatever suits you best, working under a coat on your lap or in a blacked out room, practice the process of opening the loader, putting the bits down, opening the can of bulk film, getting it out of the sealed black plastic bag, putting it into the loader the right way round, feeding the end through the slot, taping the end down so it doesn't roll itself back onto the roll, refitting the lid/cover to the loader and congratulating yourself.
Then it's practising the same approach to getting film onto spools. I did my first using the "coat on the lap" technique much to the amusement of my wife but these days work in room light.
Strappy's advice is good. Buy a £1 roll of something and dismantle it.