I agree the Broads are not as busy as they were. Now you’ve conquered the Northern section, maybe try giving the Southern rivers a go? The tidal river Yare is a wilder landscape and at some times of year you can sail all day and barely see another boat. Get up towards Brundall and you will find clubs like Coldham Hall Sailing Club and Buckenham Sailing Club to be friendly.
Usually they race on a Sunday morning but there is social sailing at other times. If you are lucky, you may even spot an Osprey in the summer; the bird, not the boat! Beccles is also a great place to visit with a club that favours youngsters and an easy walk into town from the clubhouse. There is a cantankerous old swing bridge at Reedham which, if the mood takes it, will open for you and a ferry pub that serves good food and ale. Get the tides right though, or you could find yourself sailing backwards in a force 4!
Well worth a visit.