Well thanks for not posting it if it's inappropriate.
Let me see if I can try to explain. I am a beginner-intermediate photoshop user so bear with me and there may be a better way of doing it.
OK, first I'm assuming you see some kind of menu bar on the left side when you launch Photoshop. These are the most common tools you'll use in the program.
If the image has a white background then you can simply use the eraser tool in photoshop to erase the text and then use the Text tool to retype over it. If you don't know how to find the tools just hover over them in the menu bar and photoshop will tell you the name of the tool.
If the background is not white then you can paint over it with the color of the background.
To get the right color, click on the square box in the menu that says "Select foreground color" when you hover over it. It looks like a square box. When you click on it, a "color picker" will launch and you'll see an eyedropper that will let you select a color. Use the eyedropper and click on the background of the image you want to erase. Now you've set the color to match the background and you are ready to paint over it.
Choose the brush tool and paint over the text you want to erase. Now use the Text Tool to type of it. (The text tool is a capital T)
Try that and let me know if you make any progress.