How do I edit the graphics I have uploaded to my website for use on my Photos/Docs page, Home Page, or Teacher page?

The best way to edit graphics use a dedicated graphics editing program on your computer.  You should make any desired edits on your workstation, and then upload the edited graphic to your site. This will give you the best results.

There are also a number of free online services that offer photo editing tools.  You can use an online search to find such services.