I run a shoe store and am trained in foot anatomy and care, and all the things you should be doing.
One, start off slow. It is a high impact activity and done improperly can damage your joints, go and google proper running form.
Two, you need the right support. A running shoe that laces up, bends easily and has an eva sole that absorbs some of the shock. Ideally when you press your finger into the sole of your shoe it should be squishy. And yes, wear arch supports. You do not need to go to a podiatrist or a chiropractor and get one made for you, that's stupidly expensive. If you go to a store where the staff is properly trained in how to fit you for your needs, you're set.
What you need is a full insole with at least a two degree plantar arch support, and ideally your metatarsal as well. That will be a bump in the middle of your foot, right behind the ball of your foot. The plantar arch is the big arch on the side. Now, the insole should be pretty rigid. A bit of gel in it will help absorb the shock, but do not go too squishy as that won't help at all. You need an insole and shoe that keep the proper balance of keeping your foot in a natural healthy position and giving you enough shock absorption so your knees and ankles don't take it all.
Now the insole itself will take some getting used to. It will probably feel uncomfortable, and if your feet are very flat (or you're overweight) it can actually be painful. Break yourself into them slowly as well. You're readjusting the way all the muscles in your body sit so give it time.
Running, done properly, is great exercise. Just remember: Humans were built to live on soft ground; earth and sand. The ground cushioned our steps and molded to fit out feet. Now we live on concrete, which does not mold to out feet. Our feet mold to it. So our shoes have to do the molding for us now. So try running on the grass too, it will feel better.
Hope this helps!
