Your best bet may be to learn what projectile points from your area look like, and concentrate on spotting their shape and stone type in the right places to look. What you will learn to recognize first and easiest, is projectile points. It's unlikely that bigger rocks are going to turn out to be artifacts until you actually have an eye for all types of stone tools from your region. Most of your finds, and it's the same for all of us, will be small flaked artifacts like points and scrapers. Learn the rock types used in your region for points and what points look like. Leave the other rocks alone for the time being. Nothing wrong with collecting them though, there are plenty of things to pick up besides artifacts, and it's all enjoyable.
Over the years, I've known collectors who have done extremely well hunting stream gravel bars in Kansas. Really, really well.
