First year i got some crop from black currant after i covered it in spring. Before, some kind of fly eat berries and another one stems.

I just removed cover, harvested berries and see a lot of new growth.

Question: when it's better time to remove part of new growth? Somebody told me that if i do it now, then bush will concentrate energy for next year in remaining canes. Is it right?

How many canes should i have per bush? How to detect which of old canes should i prune?

Another pruning question is about pears. When should i prune water sproats and is there any way to tell tree not to create so many water sproats?

Thanks