How do i stop blundering my pieces ??

These two things will carry you to at least 1200. Opening Principles and Tactics. Take some time to do A LOT of puzzles. Learn the motifs and the logic behind each puzzle. You will learn various checkmating ideas as well as certain tactics that win material and eventually you will start to see these things in your games. But you also have to do your best to adhere to opening principles. There are hundreds of videos on YouTube about them. 

Have you found an opening that you are comfortable with or are you still experimenting and trying to figure out your style? I would suggest you find one opening and stick with it for now. Learn the mainlines, sidelines, traps and gambits for your opening. Write them down, run them through over and over until they are burned into your memory. Use an engine to study any deviations you encounter that you are unfamiliar with to learn the best response. Do a blunder check before every move. Make sure the move you intend to play is not going cost you. Ask yourself what your opponent is trying to do with every move. 

The main thing in chess is study. It is hard work. Study every game you lose and learn why you lost so you don't repeat those same mistakes. Play longer time controls so you have more time to think about every move. It is better to play fewer high quality games and study and learn from them rather than to play 100  terrible games in a night and learn nothing from them.

Best of luck, friend.