Why did my valve pin bend? Is there anything that I can do to help it without any specialized tools? I have a new bike (been less than a month since it was purchased) and has been ridden for about 600km (375 miles) on bad city roads.
What may have caused this bend of the valve pin?   Is it possible for me to be fixing it right at home with a very basic tool kit that I have?
Should I try bending it back to the middle, or is it best to take it to a shop and have someone fix it for me?
I'd also like to know what may have caused the bend because the bike hasn't been in any crashes whatsoever, or even gone over a pothole that I would consider mighty or particularly worth noting.
You have a Schrader valve. The pin on the valve core has been bent or the core is cross threaded in the stem - the picture is a little blurry.
You can remove the core by unscrewing it from the stem. There is a special tool for that, sometimes skinny needle nose pliers can be used.
Here are the options I can think of:

If the pin is bent or the threads on the valve core are ruined you'll need a new valve core. The shops I've worked at would replace it for you for free.
If the core is cross threaded you may be able to remove it and thread it back in straight.
If the threads inside the valve stem are ruined you'll need a new tube.

Hard to say what caused the damage but it's probably related to something getting cross wise during inflation. A bent valve core pin is unrelated to road types or number of miles.