Accessing Basic.css and Theme.css
How do I download or view these two files? I don't see them in the /resources/Theme folder.
I find user.css and customStyles.css there.
These two CSS files are usually found in the template directory you are using. Editing and accessing these files are usually done when you are working with Theme Overrides (See: http://help.wildapricot.com/display/DOC/Theme+Overrides ).
For basic CSS changes, you should just be editing the User.css file.