I recomend only using a bra during bug season. They can trap moisture and make the paint color uneven over time.
Good luck with your car. With no history, I'd change all the fluids asap (incuding the trans), air filter, spark plugss, and enjoy every trouble free mile your car gives you.
I have seen cars with a bra on the front and they do protect it, but when you remove the bra you may get surprised. The rest of the paint on the car won't match the color of the paint that was under the bra and the car will look very funny. The paint fades normally in the sun and the bra covered part will not fade. That means when you eventually remove the bra, or take it off because it is worn out, you will either have to replace it or get the car painted (if you want to sell the car or drive it without the bra).
If you get one, don't get a cheap one and you shouldn't have the moisture problem as much. Anymore, rock chips n stuff isn't that big of a deal because the front bumper will never rust. Your car is going to age and road rash is just wear and tear. The bra is pretty much a dead fad and I hardly ever see anyone using one.
Now days, I've seen transparent strips that you can install on the hood of the car to help protect your paint. I forget the brand name, but if you google it, you should be able to find something. It looks way better then a bra.