I am just wondering if running for about half an hour every other day will improve my fitness, cardio etc? Thank you.

If you are currently not working out, then running for 1/2 hour every other day will help you immensely. The American Heart Association recommends 30 minutes of exercise 3x/week to maintain health. If you want to be an athlete, 30 minutes of running 3x / week is not much.

Thanks for your reply.

I don't want to be an athlete or anything. I just want to get decently fit, I find when I walk up and down my stairs a bit or do something somewhat strenuous my heart starts to beat really quickly and I get tired. So for me to have to do more than walk up and down stairs to get a really quick heart rate would be nice.

sometimes to get in shape you have to training like an athlete, after running for a few weeks and you get your fitness level up, try doing some interval training, or tabata. it can increase your stamina muscle endurance probably by 100%

That should help if your body is not use to it. You need to develop good eating habits also if your goal is to be fit.