First Select the part of image which you want to copy. Selection of image part can be using marquee tool. The marquee tool allows you to click and drag an area of an image, thus selecting it. Select marquee tool. Marquee tool is show below.
Now select the image part using this tool, selected area [...]

If you have messed tools setting in photoshop, than you can reset it to default setting. Click and hold the left area of the tool option bar. A window will pop-up and will show you two option. Select “reset all tools”. A popup will ask for conformation, click Ok.

To create a new document in photoshop follow these steps;

Open photoshop.
Click “File” in menu option, and than select “New”. 

You see get a windows like this.

Give a name to your new document, and size of your new image document. Next thing you need to set is resolution and background of your new photoshop document. You [...]