Hi Matt,
Disney's Beach Club Resort is such a fun resort. My family loves the quaint atmosphere and the quick walking distance to Epcot.
Getting an upgrade to your resort room is a wonderful surprise if it happens; however, I never count on it happening since upgrades are infrequent. I suggest that you book the room level that you want and assume that is what you will get. That way, if an upgrade happens, it is all positive, and if not, you will still be happy with the room that you have.
The garden view rooms at Disney's Beach Club resort will have views of gardens. Since garden view rooms at Disney's Beach Club are spread throughout the resort, you should probably think about what you are most interested in being close to in order to make a room request. If proximity to the pool, the bus stop, or Epcot are most important, you could note this as a request. You could also request a room in a quieter area if that is important to you. Please do know that any request is not a guarantee, though Disney will do their best to try to honor the request.
I hope that this information is helpful, Matt. Please do not hesitate to ask if you have any further questions!