Honestly, it's not that bad. Without spoiling anything, you'll get use to the Alien and start to learn how it behaves. It's smart, sure, but you'll eventually start learning what you should and shouldn't do when it's around. That said, if it's your first time playing, I wouldn't recommend playing at night with the lights off
Pro Tip: Don't sprint. Ever. ->
If you want specifics, feel free to PM me. I've already 100% the game, so I've picked up some tips along the way.