| Welcome aboard.
There are two covers inspection and derby cover. Inspection is a small oval cover. You usually fill through the derby cover. Both are held on by Torx-Plus fasteners which are like a step between sizes. The Torx socket must fit tightly into it's socket or it will strip the head out.
I also suggest a service manual if you don't have one already even though this is not very well covered in it. | 
