When you're just starting out, you should simply go to a store where the staff do a quick analysis for you - takes about 10 minutes and doesn't cost extra. Most stores either have a little treadmill camera or they'll just watch how your foot lands. That's really the difference between shoes that support your natural movement and ones that work against it.
If you just blindly buy whatever, you often don't notice until a bit later - then your knees start to ache or your heel hurts. Beginners put extra strain on their joints anyway, because your running muscles aren't stable enough yet. With a properly fitted shoe, you'll probably save yourself months of frustration and possible training breaks.
The good news: you don't have to get the most expensive model. Most manufacturers have solid beginner models in different categories (neutral, stability, etc.). Get some advice on what kind of gait you have, then pick something that fits your budget, and you're good to go.