finding a mooring where you want, put it this way, have a plan B and a plan c , the popular moorings frequently fill up quickly, and even if you have only just set sail, if there is a mooring at horning staithe, you have to go for it, as it may be the only time you manage it. hookups at broads authority moorings take a card, these cost around £1 (been a while since i bought one) and can be obtained at the broads authority HQ, some shops have them, and the rangers have them if you see them, the BA office at ranworth has them too. (i am sure others will chip in with other places they can be obtained.
pubs with hookup, you will probably have to go in to pay, some pubs charge for moorings too.
oulton broad and beccles have their own systems, beccles has different cards, oulton broad you pay more to use the hookup