Instead of introducing all the PhotoShop tools to you, I’m just going to tell you about the ones you’ll need for cropping, changing brightness/contrast, and changing the resolution of your image.
Over to the left on your workspace should be a floating Tools Palette. It may be shown as one long column, or a shorter two-column palette. If you want to change to either format, just click on the right side at the very top.
The Move Tool
The Move tool is very important. If you aren’t in the middle of using a different tool, like cropping a picture, you should be using this tool. Get in the habit of clicking on it when you finish with a function.
The Crop Tool
Usually when I open a new picture, I crop it first. If I don’t like it, I use Edit > Undo until I get it right. When you are done cropping, click on the Move tool and you will get a screen that asks if you want to crop, or cancel? Click accordingly.
The Hand Tool
The Hand tool moves your image around, just like if you placed your hand on it.
The Zoom Tool
There are several ways to zoom in and out. You can use this tool, or, since I have a Mac, I use command + or command -. If you use the zoom tool, look up at the top of your screen and you’ll see a magnifying glass with a “-” in it for zooming out.