Hello! Yeah all great questions, your deck determines your suit and the suit determines your type and thus the damage effectiveness. So the suit below your health and the opponents is the type. Ideally if this is followed, matches are quicker.
Unfortunately, we did not have a lot of time to make an in depth tutorial for the jam so if we revist the game, we will make sure to add that and make things more clear and fast paced.
Glad you enjoyed the concept though!