replacing tires
 

if i change my front left tire, would i have to also change the front right. if i didn't would i notice a difference while i am driving?

If you put the same size and type, I don't think you can notice, and if you have DSC it probably won't notice, but if the right front is worn a lot it might.

Apparently your front right is still good or you'd already just replace both.

Also, believe it or not best and newest tires should go on rear first.

Why don't you put the new one on the left rear, and move the left rear to the left front.

Depends on the difference in depth of tread between the two tires... assuming that they are of the same type, size, tread pattern and air pressure. The greater the difference, the more noticeable the change in handling.

Depending on how much wear the right front tire has compared to a new tire it could cause the car to pull, it could also cause problems with the ABS and Traction Control Systems. So it may or may not cause you problems

What is the reason for replacing only one tire? Irregular tread wear pattern? If so, get an alignment check or you may be changing tires quite often.

It's better to change both front tires for even wear and grip, but it also depends on how much thread is left on the other tire.

Im replacing it because i got a hole in it and it went flat

In my opinion bite the bullet and change the pair if the tread difference between the new tire and the other tire is going be more substantial. I'd say 3-4/32nd or more.

I always change tires in pairs. Make sure you put the new pair on the rear though.