i am working on a dio of tracked and wheeled vehicles parked on a gravel road and i am very new to weathering so i was wondering if anyone could give me some pointers on how to weather the vehicles to make them look like they have been traveling for some time down the roads

Hi Jeff,
Welcome to Armorama! Gravel and dirt roads tend to kick up dust. You can replicate this most easily with a light colored pigment dusted on the vehicle, starting heavier on the underside and moving up the vehicle. Or, a light misting of Tamiya Buff with your airbrush will give you an excellent dust effect.

a real heavy filter with tamiya buff will do a pretty good job too

Just as a side note, gravel is always local stone, and colors vary quite a bit. I would use a light dusting of the color of the gravel you've decided on for your diorama.