If you're going to be playing Windrunner, more than likely, you'll be doing it in a support role... I'd recommend losing the Phase Boots and going for Arcane. You'll love the extra mana, simply so you're able to spam Arcane Shot and Shackle onto the enemy in your lane and your carries will love you for it as well, as you're able to provide the extra mana for their abilities. And don't forget courier/wards!
That being said, the one reason she's mega-decent to play with as a newb is because of her escape mechanic (Windrun). Try to play with heroes who're similar to her in that respect, Mirana is another. Leap and her Ulti are a great way of saving you from trouble a lot of the time and it'll help you last a lot longer in every game you play. Obviously with Mirana's ult, try to use it with a bit of common sense
Puck's another hero who can turn the tide of fights, but also has amazing escape abilities... but that's a hero for you to try when you've got a better grasp of the game.
When I started, I played just Windrunner until I was comfortable with understanding the game mechanics... what certain heroes were capable of, and what the items available can do. Then I moved onto different heroes, like Sand King (good melee hero to learn with), Sniper, Disruptor, Dragon Knight, Earthshaker, Bloodseeker... and by this point you probably know the game backwards. Not to say you need to follow that line of enquiry, they were just the heroes I felt comfortable playing at the time.
Also, try Jakiro. He's a fantastic hero who scales with skill... but his abilities allow for even the newest of players to cause mayhem during team fights.