U Can try add Begin for first query before for rec and add END also after end loop, like below

BEGIN FOR rec IN ( SELECT food_name, food_type, food_qty FROM food_tbl WHERE food_type = 'C') LOOP INSERT INTO candy_tbl(candy_name, candy_type, candy_qty) VALUES(rec.food_name, rec.food_type, rec.food_qty) END LOOP; END;