It's been a while, but start off easy. Get a feel of the game. And when you get a skill or a talisman? USE IT! And don't go and attack every bile animal you see. Trust me, I've tried, and it doesn't end well. Take a couple of 'em out, sure, but as you get into the harder levels, try to avoid them when you can. It'll help conserve your health and not get rid of skills you'll truly need later(you might get stuck and surrounded accidentally before you get to the show-down, it happens). If you happen to get ahead of yourself on the hard mission and you have to level up before moving on, do some of the easier ones. Do the training with your spirit animal in the Your Room place. Just get XP. Oh, and on level forty? When you're fighting what's-her-face? And you've finally defeated her? MAKE SURE YOU ARE IN AN OPEN AREA. DO NOT GO NEAR BUSHES OR TREES THAT COULD POSSIBLY BLOCK YOUR AVATAR. TRUST ME ON THIS. I've had to re-do the mission several times because of this.
Hope it helps! :)