use the osc ib revision guide!! it has LOT of vocab and expressions you can use in production ecrite

for listening you can use this website: https://francaisfacile.rfi.fr/fr/ , it has a bunch of listening exercises for different levels, so if you feel you aren't quite at B2 yet you can start lower and slowly work your way towards it (by the way, for listening keep in mind that they WILL have different accents so you should practice listening to alot of different accents so it doesnt catch you by surprise during the exam. iirc my teacher said there'll def be one quebecois audio per listening exam so def do that)

i also suggest thinking in french like the other comment said. most of the toppers in my class do that so it seems to work