Okay. So when it comes to muting strings there are quite a few videos on YouTube that can explain it better than I can. Probably. All that I can say is that you need to experiment with your wrist and your palm as far as that goes.
Like I said before, having a good tuner (like one that you would clip on to your headstock that's powered by a small battery), decent strings, and a decent guitar is going to make quite a bit of difference. I know there are a lot of cheap ass guitars out there being sold for about $100 or less. But the truth is if you just spend the money and get around a $300 guitar, it will make a world of difference.