When you double-click on a CR2 file (a raw Canon photo), it should open in Photoshop

Click and drag the different bars on the right side until you're happy with the picture. You can always try the Auto option as a starting point. Here's the breakdown for what each level means:

Photoshop Adjustments Explained

Once you're done editing the image, click on the Open Image button on the bottom.

Now that the file is opened normally, you need to save it as a TIF. To do this, go to File > Save As.

Change the file type to TIF.

Make sure you save it in a "Best - Edited" folder under the category the photo should go in.

In the next window, leave things as they are, and click OK.