I am brand new to this product. I want to be able to edit a photo (crop, sharpen, etc.), then apply keywords. Can I do this inside Bridge, or do I have to go out to edit and back in to apply keywords?
You can do some editing in Camera RAW but only if you have a paid subscription. For anything beyond very minor edits, you'll need to use an application like Photoshop and then do metadata operations in Bridge. Bridge is an organizer and viewer, NOT an image editor.
But to use Adobe Camera Raw, you must have one of the Photoshop Plans, it does not work unless you have Photoshop on your computer as well.
The first set of activities you want to do (crop, sharpen, etc.) are done in either Phothsop or ACR, the last one, keywording, can be done in either Photoshop or Bridge.