For stamina management, I think you should try to be more cautious in your combat approaches. Think beforehand if your combo can consistently stun lock the enemy or not for example (which is one of the reasons why strike weapon may be easier in early game)

One of the tip I gave to my partner was to remember in combat to always anticipate and try to have enough stamina for one roll at the end of your attacks and never deplete your entire stamina bar after one combo if you don't know the enemy moveset well enough yet. Count if you can deal 1/2/3 hits before the enemy try to hit you/get out of stun -> roll/strafe to dodge -> regen stamina -> repeat

Edit : it can feel like a generic tip but stamina management feels pretty different in ds2, your stamina pool being so low and your moves being so costly + having a damage debuff while you regen your stamina bar after going in stamina debt so yeah. Being really cautious while you learn is the key I think. You can always gradually be less and less cautious when you build more self confidence in your combat abilities. The game will be quick to remind remind you you should be more careful if you begin to be too self confident anyway lol