You can create, copy, move, rename, and delete files and directories by using Nautilus, but before you can do any of these things, you need to select a file or directory. Selecting files is something you will be doing a lot, so let's start with that. Place your mouse cursor just outside one of the icons of your choosing. Now, drag the cursor across the icon and notice the highlight box you are creating as you drag. You'll know a file is selected because it becomes highlighted. Right-clicking also selects a file but in a somewhat different way, bringing up a menu dialog that then asks you what you want to do with that file.
Don't forget your cursor keys either. Moving left, right, up, or down highlights whatever file or directory you happen to be sitting on. You can then click on Edit in the menu bar (or press <Alt+E> to get to the Edit menu) and decide what it is you want to do with the file. I'll talk about those decisions in a moment.
Sometimes, one file just isn't enoughyou need to select multiple files. The easiest way of all is with the mouse. Left-click to the top and left of the icon you want to start with, then drag your cursor across a series of icons. Notice again the highlight box that surrounds the files and directories you select. Perhaps you just want a file here and a file there. How do you pick and choose multiple files, you ask? Simply hold down the <Ctrl> key and click with the mouse. Let's say that you have selected a group of four files, and you want one further down in your directory. Let go of the mouse button (but keep holding down the <Ctrl> key), position your mouse to the top and left of the next group of icons, and select away. As long as you continue to hold down the <Ctrl> key, you can pick up and select files here and there at will.
It is also possible to do all these things with the cursor keys by simply moving your cursor over the file you want to start with, holding down the <Shift> key, and moving the cursor to the left (or whatever direction you like). As you do this, you'll notice file after file being selected. Try it for yourself. For nonsequential selection, use the <Ctrl> key as you did with the mouse. Select (or deselect) the files by pressing the spacebar. When your cursor is sitting on the file you want, press the spacebar, and your files will be highlighted.
Finally, and probably quite important for the future, you can also select by extension. Let's say that you want to select all the files with an .mp3 or .doc extension in your directory. Click Edit on the menu bar, then click Select Pattern. A small window pops up, asking you for an extension. If you want all the .mp3 files, you enter *.mp3. The .mp3 extension limits your selection to a certain type of file, whereas the asterisk says, "give me everything" that matches.