my gradient fill doesn't show as a gradient, it just shows as 1 color

If you have two colors in the Edit Gradient panel and only see one color in the shape, the start and end points of the gradient are not in the right place.

thank you for the help! i'm using an alternate account so thats why my username is different. the track matte\luma matte thing worked

You need to use Selection tool to reposition your gradient as it starts from the centre of the comp by default.

I would approach it differently. Create a solid layer and then add the gradient effect with the black on top and white on the bottom. Place the gradient above your shape. In the timeline go to track matte (you may have to click toggle switches and modes to track matte and modes.) On the shape layer point it to drop down on track matte to luma matte and whatever you name the name of the solid layer is. The lightest parts should show your shape and the darkest parts should become more invisible the to match the darkness of the gradient.