|If the mouse pointer is a hand, that means you can click on whatever is under the hand and something will happen. If you hold down the click button and drag the mouse, you might be able to pull something on the screen. Sometimes, to make something happen with the mouse, you have to click on it twice.
If the mouse pointer looks like an I, it probably means you can write something. Move the pointer to the place you want to write, and click once. Then you can use the keyboard to type something there. You can also click on some text, hold down the clicker, and drag the mouse over the text. Then you highlight that text. You can then copy it, cut it, or paste it somewhere else.