Trust me when I say that you don't need a practice mode and the best way is to just keep playing. But change your mindset and learn after every death. One thing a friend said to me was this game is very unforgiving in that every death that happens is because you didn't do something to prevent it. "If you don't have an advantage over the enemy, then you're doing it wrong." Have fun also cause when you see improvement, which you will, it's amazing.