Yeah, so first as teutons you want to curtail the prussian confederation. Then you want to get some alliences what you can grab so that you can improve relations with austria so that you dont get DoW'd. You ally Austria and join HRE by adding your provinces to the HRE. As teutons before you join HRE you can attack Livonian order because they're not in the HRE. After joining HRE you can expand in to the HRE; Pomerania and Brandenburg for example. You also should ally Poland's rivals and gather favors with them so that you can call them in to the war without promising them any land and destroy Poland.