SQL & PL/SQL

I have an open-book assignment to do for a PL/SQL class, but I don't even know where to begin. The assignment is this:

Create a procedure, SHOP_SALES_NUM, to populate BB_SHOP_SALES

-Base tables for the data for the column in BB_SHOP SALES are BB_SHOPPER and BB_BASKET and orderplaced = 1
-Total price is an aggregated calculated field including only product amounts (quantity* price) and does NOT include shipping and tax
-All shoppers are to be processed (HINT: Cursor)

All I've got so far:

CURSOR shop_sales IS
SELECT s.firstname, s.lastname, b.idbasket, b.idshopper, b.quantity, b.subtotal
FROM bb_shopper s, bb_basket b
WHERE orderplaced = 1;
CREATE OR REPLACE PROCEDURE shop_sales_num (
fname IN bb_shopper.firstname%TYPE,
lname IN bb_shopper.lastname%TYPE,
bid IN bb_basket.idbasket%TYPE,
sid IN bb_basket.idshopper%TYPE,
qty IN bb_basket.quantity%TYPE,
sub IN bb_basket.subtotal%TYPE);
IS
BEGIN
UPDATE bb_shop_sales
END;

Obviously, it's incomplete and I don't even know if I'm on the right track. Can anyone help me solve this?