Which is better, mustang or jeep?
Heres the thing kid, your first car is not your dream car.
you will have it for a while, but it is not the end of the earth if you dont 'like' it
If it gets you A to B you should appreciate that, and not be picky and say 'oh i dont like any cars but mustangs and jeeps of this specific year'
As a first you get what you can (and what you can easily afford)
As for what is better? if you get a v6 mustang it will truck on forever and ever, i mean 200k miles as long as you are not stupid driving it.
It will be more expensive to insure because of the mustang name, but if you can manage that because you save money on purchase price then that is ok.
But too, the jeep will truck on just as long as long as it has not been offroading. it would likely be cheaper and cheaper to insure. Gas mileage is irrelevant between your choices, as it is mediocre either way.
Up to you
but i would consider what i said about your first car, and just get something that will go reliably and be more fun as a light weight car instead of an suv or sports car-ish