how can i improve my photoshop skills .?

Yes, to learn photoshop tutorials are a good resource. But keep in mind, Photoshop is just your toolbox, you'll still need your head/creativity to create cool stuff.

But also basic creativity can be "learned" somehow, because design follows rules that can be learned. Keep particing, go with open eyes through your life and think about how other solved design issues. Start watching creative blogs, look at advertisements and play around.